diff --git a/resources/sql/autopatches/20141210.maniphestsubscribersmig.1.sql b/resources/sql/autopatches/20141210.maniphestsubscribersmig.1.sql
new file mode 100644
--- /dev/null
+++ b/resources/sql/autopatches/20141210.maniphestsubscribersmig.1.sql
@@ -0,0 +1,9 @@
+INSERT IGNORE INTO {$NAMESPACE}_maniphest.edge (src, type, dst)
+  SELECT taskPHID, 21, subscriberPHID
+  FROM {$NAMESPACE}_maniphest.maniphest_tasksubscriber
+  WHERE subscriberPHID != '';
+
+INSERT IGNORE INTO {$NAMESPACE}_maniphest.edge (src, type, dst)
+  SELECT subscriberPHID, 22, taskPHID
+  FROM {$NAMESPACE}_maniphest.maniphest_tasksubscriber
+  WHERE subscriberPHID != '';
diff --git a/resources/sql/autopatches/20141210.maniphestsubscribersmig.2.sql b/resources/sql/autopatches/20141210.maniphestsubscribersmig.2.sql
new file mode 100644
--- /dev/null
+++ b/resources/sql/autopatches/20141210.maniphestsubscribersmig.2.sql
@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_maniphest.maniphest_task
+  DROP ccPHIDs;
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -1001,7 +1001,6 @@
     'ManiphestSearchIndexer' => 'applications/maniphest/search/ManiphestSearchIndexer.php',
     'ManiphestStatusConfigOptionType' => 'applications/maniphest/config/ManiphestStatusConfigOptionType.php',
     'ManiphestSubpriorityController' => 'applications/maniphest/controller/ManiphestSubpriorityController.php',
-    'ManiphestSubscribeController' => 'applications/maniphest/controller/ManiphestSubscribeController.php',
     'ManiphestTask' => 'applications/maniphest/storage/ManiphestTask.php',
     'ManiphestTaskDescriptionPreviewController' => 'applications/maniphest/controller/ManiphestTaskDescriptionPreviewController.php',
     'ManiphestTaskDetailController' => 'applications/maniphest/controller/ManiphestTaskDetailController.php',
@@ -4072,9 +4071,9 @@
     'ManiphestSearchIndexer' => 'PhabricatorSearchDocumentIndexer',
     'ManiphestStatusConfigOptionType' => 'PhabricatorConfigJSONOptionType',
     'ManiphestSubpriorityController' => 'ManiphestController',
-    'ManiphestSubscribeController' => 'ManiphestController',
     'ManiphestTask' => array(
       'ManiphestDAO',
+      'PhabricatorSubscribableInterface',
       'PhabricatorMarkupInterface',
       'PhabricatorPolicyInterface',
       'PhabricatorTokenReceiverInterface',
diff --git a/src/applications/herald/adapter/HeraldManiphestTaskAdapter.php b/src/applications/herald/adapter/HeraldManiphestTaskAdapter.php
--- a/src/applications/herald/adapter/HeraldManiphestTaskAdapter.php
+++ b/src/applications/herald/adapter/HeraldManiphestTaskAdapter.php
@@ -139,7 +139,7 @@
       case self::FIELD_ASSIGNEE:
         return $this->getTask()->getOwnerPHID();
       case self::FIELD_CC:
-        return $this->getTask()->getCCPHIDs();
+        return $this->getTask()->getSubscriberPHIDs();
       case self::FIELD_PROJECTS:
         return PhabricatorEdgeQuery::loadDestinationPHIDs(
           $this->getTask()->getPHID(),
diff --git a/src/applications/maniphest/application/PhabricatorManiphestApplication.php b/src/applications/maniphest/application/PhabricatorManiphestApplication.php
--- a/src/applications/maniphest/application/PhabricatorManiphestApplication.php
+++ b/src/applications/maniphest/application/PhabricatorManiphestApplication.php
@@ -66,8 +66,6 @@
         ),
         'export/(?P<key>[^/]+)/' => 'ManiphestExportController',
         'subpriority/' => 'ManiphestSubpriorityController',
-        'subscribe/(?P<action>add|rem)/(?P<id>[1-9]\d*)/'
-          => 'ManiphestSubscribeController',
       ),
     );
   }
diff --git a/src/applications/maniphest/conduit/ManiphestConduitAPIMethod.php b/src/applications/maniphest/conduit/ManiphestConduitAPIMethod.php
--- a/src/applications/maniphest/conduit/ManiphestConduitAPIMethod.php
+++ b/src/applications/maniphest/conduit/ManiphestConduitAPIMethod.php
@@ -62,6 +62,8 @@
       $task->setDescription((string)$request->getValue('description'));
       $changes[ManiphestTransaction::TYPE_STATUS] =
         ManiphestTaskStatus::getDefaultStatus();
+      $changes[PhabricatorTransactions::TYPE_SUBSCRIBERS] =
+        array('+' => array($request->getUser()->getPHID()));
     } else {
 
       $comments = $request->getValue('comments');
@@ -111,7 +113,8 @@
 
     $ccs = $request->getValue('ccPHIDs');
     if ($ccs !== null) {
-      $changes[ManiphestTransaction::TYPE_CCS] = $ccs;
+      $changes[PhabricatorTransactions::TYPE_SUBSCRIBERS] =
+        array('=' => array_fuse($ccs));
     }
 
     $transactions = array();
@@ -228,6 +231,13 @@
     $event->setUser($request->getUser());
     $event->setConduitRequest($request);
     PhutilEventEngine::dispatchEvent($event);
+
+    // reload the task now that we've done all the fun stuff
+    return id(new ManiphestTaskQuery())
+      ->setViewer($request->getUser())
+      ->withPHIDs(array($task->getPHID()))
+      ->needSubscriberPHIDs(true)
+      ->executeOne();
   }
 
   protected function buildTaskInfoDictionaries(array $tasks) {
@@ -265,7 +275,7 @@
         'phid'         => $task->getPHID(),
         'authorPHID'   => $task->getAuthorPHID(),
         'ownerPHID'    => $task->getOwnerPHID(),
-        'ccPHIDs'      => $task->getCCPHIDs(),
+        'ccPHIDs'      => $task->getSubscriberPHIDs(),
         'status'       => $task->getStatus(),
         'statusName'   => ManiphestTaskStatus::getTaskStatusName(
           $task->getStatus()),
diff --git a/src/applications/maniphest/conduit/ManiphestCreateTaskConduitAPIMethod.php b/src/applications/maniphest/conduit/ManiphestCreateTaskConduitAPIMethod.php
--- a/src/applications/maniphest/conduit/ManiphestCreateTaskConduitAPIMethod.php
+++ b/src/applications/maniphest/conduit/ManiphestCreateTaskConduitAPIMethod.php
@@ -28,7 +28,7 @@
   protected function execute(ConduitAPIRequest $request) {
     $task = ManiphestTask::initializeNewTask($request->getUser());
 
-    $this->applyRequest($task, $request, $is_new = true);
+    $task = $this->applyRequest($task, $request, $is_new = true);
 
     return $this->buildTaskInfoDictionary($task);
   }
diff --git a/src/applications/maniphest/conduit/ManiphestInfoConduitAPIMethod.php b/src/applications/maniphest/conduit/ManiphestInfoConduitAPIMethod.php
--- a/src/applications/maniphest/conduit/ManiphestInfoConduitAPIMethod.php
+++ b/src/applications/maniphest/conduit/ManiphestInfoConduitAPIMethod.php
@@ -32,6 +32,7 @@
     $task = id(new ManiphestTaskQuery())
       ->setViewer($request->getUser())
       ->withIDs(array($task_id))
+      ->needSubscriberPHIDs(true)
       ->executeOne();
     if (!$task) {
       throw new ConduitException('ERR_BAD_TASK');
diff --git a/src/applications/maniphest/conduit/ManiphestQueryConduitAPIMethod.php b/src/applications/maniphest/conduit/ManiphestQueryConduitAPIMethod.php
--- a/src/applications/maniphest/conduit/ManiphestQueryConduitAPIMethod.php
+++ b/src/applications/maniphest/conduit/ManiphestQueryConduitAPIMethod.php
@@ -64,6 +64,7 @@
     $query = new ManiphestTaskQuery();
 
     $query->setViewer($request->getUser());
+    $query->needSubscriberPHIDs(true);
 
     $task_ids = $request->getValue('ids');
     if ($task_ids) {
diff --git a/src/applications/maniphest/conduit/ManiphestUpdateConduitAPIMethod.php b/src/applications/maniphest/conduit/ManiphestUpdateConduitAPIMethod.php
--- a/src/applications/maniphest/conduit/ManiphestUpdateConduitAPIMethod.php
+++ b/src/applications/maniphest/conduit/ManiphestUpdateConduitAPIMethod.php
@@ -38,11 +38,13 @@
       $task = id(new ManiphestTaskQuery())
         ->setViewer($request->getUser())
         ->withIDs(array($id))
+        ->needSubscriberPHIDs(true)
         ->executeOne();
     } else {
       $task = id(new ManiphestTaskQuery())
         ->setViewer($request->getUser())
         ->withPHIDs(array($phid))
+        ->needSubscriberPHIDs(true)
         ->executeOne();
     }
 
@@ -58,7 +60,7 @@
       throw new ConduitException('ERR-BAD-TASK');
     }
 
-    $this->applyRequest($task, $request, $is_new = false);
+    $task = $this->applyRequest($task, $request, $is_new = false);
 
     return $this->buildTaskInfoDictionary($task);
   }
diff --git a/src/applications/maniphest/controller/ManiphestBatchEditController.php b/src/applications/maniphest/controller/ManiphestBatchEditController.php
--- a/src/applications/maniphest/controller/ManiphestBatchEditController.php
+++ b/src/applications/maniphest/controller/ManiphestBatchEditController.php
@@ -18,6 +18,7 @@
           PhabricatorPolicyCapability::CAN_VIEW,
           PhabricatorPolicyCapability::CAN_EDIT,
         ))
+      ->needSubscriberPHIDs(true)
       ->execute();
 
     $actions = $request->getStr('actions');
@@ -171,8 +172,8 @@
       'priority'        => ManiphestTransaction::TYPE_PRIORITY,
       'add_project'     => ManiphestTransaction::TYPE_PROJECTS,
       'remove_project'  => ManiphestTransaction::TYPE_PROJECTS,
-      'add_ccs'         => ManiphestTransaction::TYPE_CCS,
-      'remove_ccs'      => ManiphestTransaction::TYPE_CCS,
+      'add_ccs'         => PhabricatorTransactions::TYPE_SUBSCRIBERS,
+      'remove_ccs'      => PhabricatorTransactions::TYPE_SUBSCRIBERS,
     );
 
     $edge_edit_types = array(
@@ -215,8 +216,8 @@
           case ManiphestTransaction::TYPE_PROJECTS:
             $current = $task->getProjectPHIDs();
             break;
-          case ManiphestTransaction::TYPE_CCS:
-            $current = $task->getCCPHIDs();
+          case PhabricatorTransactions::TYPE_SUBSCRIBERS:
+            $current = $task->getSubscriberPHIDs();
             break;
         }
       }
@@ -246,7 +247,7 @@
             continue 2;
           }
           break;
-        case ManiphestTransaction::TYPE_CCS:
+        case PhabricatorTransactions::TYPE_SUBSCRIBERS:
           if (empty($value)) {
             continue 2;
           }
@@ -274,12 +275,7 @@
           }
           break;
         case ManiphestTransaction::TYPE_PROJECTS:
-        case ManiphestTransaction::TYPE_CCS:
-          $remove_actions = array(
-            'remove_project' => true,
-            'remove_ccs'    => true,
-          );
-          $is_remove = isset($remove_actions[$action['action']]);
+          $is_remove = $action['action'] == 'remove_project';
 
           $current = array_fill_keys($current, true);
           $value   = array_fill_keys($value, true);
@@ -309,6 +305,39 @@
 
           $value = array_keys($new);
           break;
+        case PhabricatorTransactions::TYPE_SUBSCRIBERS:
+          $is_remove = $action['action'] == 'remove_ccs';
+
+          $current = array_fill_keys($current, true);
+
+          $new = array();
+          $did_something = false;
+
+          if ($is_remove) {
+            foreach ($value as $phid) {
+              if (isset($current[$phid])) {
+                $new[$phid] = true;
+                $did_something = true;
+              }
+            }
+            if ($new) {
+              $value = array('-' => array_keys($new));
+            }
+          } else {
+            $new = array();
+            foreach ($value as $phid) {
+              $new[$phid] = true;
+              $did_something = true;
+            }
+            if ($new) {
+              $value = array('+' => array_keys($new));
+            }
+          }
+          if (!$did_something) {
+            continue 2;
+          }
+
+          break;
       }
 
       $value_map[$type] = $value;
diff --git a/src/applications/maniphest/controller/ManiphestSubscribeController.php b/src/applications/maniphest/controller/ManiphestSubscribeController.php
deleted file mode 100644
--- a/src/applications/maniphest/controller/ManiphestSubscribeController.php
+++ /dev/null
@@ -1,51 +0,0 @@
-<?php
-
-final class ManiphestSubscribeController extends ManiphestController {
-
-  private $id;
-  private $action;
-
-  public function willProcessRequest(array $data) {
-    $this->id = $data['id'];
-    $this->action = $data['action'];
-  }
-
-  public function processRequest() {
-
-    $request = $this->getRequest();
-    $user = $request->getUser();
-
-    $task = id(new ManiphestTaskQuery())
-      ->setViewer($user)
-      ->withIDs(array($this->id))
-      ->executeOne();
-    if (!$task) {
-      return new Aphront404Response();
-    }
-
-    $ccs = $task->getCCPHIDs();
-    switch ($this->action) {
-      case 'add':
-        $ccs[] = $user->getPHID();
-        break;
-      case 'rem':
-        $ccs = array_diff($ccs, array($user->getPHID()));
-        break;
-      default:
-        return new Aphront400Response();
-    }
-
-    $xaction = id(new ManiphestTransaction())
-      ->setTransactionType(ManiphestTransaction::TYPE_CCS)
-      ->setNewValue($ccs);
-
-    $editor = id(new ManiphestTransactionEditor())
-      ->setActor($user)
-      ->setContentSourceFromRequest($request)
-      ->setContinueOnNoEffect(true)
-      ->setContinueOnMissingFields(true)
-      ->applyTransactions($task, array($xaction));
-
-    return id(new AphrontRedirectResponse())->setURI('/T'.$task->getID());
-  }
-}
diff --git a/src/applications/maniphest/controller/ManiphestTaskDetailController.php b/src/applications/maniphest/controller/ManiphestTaskDetailController.php
--- a/src/applications/maniphest/controller/ManiphestTaskDetailController.php
+++ b/src/applications/maniphest/controller/ManiphestTaskDetailController.php
@@ -23,6 +23,7 @@
     $task = id(new ManiphestTaskQuery())
       ->setViewer($user)
       ->withIDs(array($this->id))
+      ->needSubscriberPHIDs(true)
       ->executeOne();
     if (!$task) {
       return new Aphront404Response();
@@ -65,12 +66,6 @@
     $edges = idx($query->execute(), $phid);
     $phids = array_fill_keys($query->getDestinationPHIDs(), true);
 
-    foreach ($task->getCCPHIDs() as $phid) {
-      $phids[$phid] = true;
-    }
-    foreach ($task->getProjectPHIDs() as $phid) {
-      $phids[$phid] = true;
-    }
     if ($task->getOwnerPHID()) {
       $phids[$task->getOwnerPHID()] = true;
     }
@@ -139,12 +134,12 @@
     $resolution_types = ManiphestTaskStatus::getTaskStatusMap();
 
     $transaction_types = array(
-      PhabricatorTransactions::TYPE_COMMENT => pht('Comment'),
-      ManiphestTransaction::TYPE_STATUS     => pht('Change Status'),
-      ManiphestTransaction::TYPE_OWNER      => pht('Reassign / Claim'),
-      ManiphestTransaction::TYPE_CCS        => pht('Add CCs'),
-      ManiphestTransaction::TYPE_PRIORITY   => pht('Change Priority'),
-      ManiphestTransaction::TYPE_PROJECTS   => pht('Associate Projects'),
+      PhabricatorTransactions::TYPE_COMMENT     => pht('Comment'),
+      ManiphestTransaction::TYPE_STATUS         => pht('Change Status'),
+      ManiphestTransaction::TYPE_OWNER          => pht('Reassign / Claim'),
+      PhabricatorTransactions::TYPE_SUBSCRIBERS => pht('Add CCs'),
+      ManiphestTransaction::TYPE_PRIORITY       => pht('Change Priority'),
+      ManiphestTransaction::TYPE_PROJECTS       => pht('Associate Projects'),
     );
 
     // Remove actions the user doesn't have permission to take.
@@ -265,11 +260,11 @@
           ->setValue(pht('Submit')));
 
     $control_map = array(
-      ManiphestTransaction::TYPE_STATUS   => 'resolution',
-      ManiphestTransaction::TYPE_OWNER    => 'assign_to',
-      ManiphestTransaction::TYPE_CCS      => 'ccs',
-      ManiphestTransaction::TYPE_PRIORITY => 'priority',
-      ManiphestTransaction::TYPE_PROJECTS => 'projects',
+      ManiphestTransaction::TYPE_STATUS         => 'resolution',
+      ManiphestTransaction::TYPE_OWNER          => 'assign_to',
+      PhabricatorTransactions::TYPE_SUBSCRIBERS => 'ccs',
+      ManiphestTransaction::TYPE_PRIORITY       => 'priority',
+      ManiphestTransaction::TYPE_PROJECTS       => 'projects',
     );
 
     $projects_source = new PhabricatorProjectDatasource();
@@ -289,7 +284,7 @@
         'limit'       => 1,
         'placeholder' => $users_source->getPlaceholderText(),
       ),
-      ManiphestTransaction::TYPE_CCS => array(
+      PhabricatorTransactions::TYPE_SUBSCRIBERS => array(
         'id'          => 'cc-tokenizer',
         'src'         => $mailable_source->getDatasourceURI(),
         'placeholder' => $mailable_source->getPlaceholderText(),
@@ -397,7 +392,6 @@
   private function buildActionView(ManiphestTask $task) {
     $viewer = $this->getRequest()->getUser();
     $viewer_phid = $viewer->getPHID();
-    $viewer_is_cc = in_array($viewer_phid, $task->getCCPHIDs());
 
     $id = $task->getID();
     $phid = $task->getPHID();
@@ -420,26 +414,6 @@
         ->setDisabled(!$can_edit)
         ->setWorkflow(!$can_edit));
 
-    if ($task->getOwnerPHID() === $viewer_phid) {
-      $view->addAction(
-        id(new PhabricatorActionView())
-          ->setName(pht('Automatically Subscribed'))
-          ->setDisabled(true)
-          ->setIcon('fa-check-circle'));
-    } else {
-      $action = $viewer_is_cc ? 'rem' : 'add';
-      $name   = $viewer_is_cc ? pht('Unsubscribe') : pht('Subscribe');
-      $icon   = $viewer_is_cc ? 'fa-minus-circle' : 'fa-plus-circle';
-
-      $view->addAction(
-        id(new PhabricatorActionView())
-          ->setName($name)
-          ->setHref("/maniphest/subscribe/{$action}/{$id}/")
-          ->setRenderAsForm(true)
-          ->setUser($viewer)
-          ->setIcon($icon));
-    }
-
     $view->addAction(
       id(new PhabricatorActionView())
         ->setName(pht('Merge Duplicates In'))
@@ -490,14 +464,6 @@
       pht('Priority'),
       ManiphestTaskPriority::getTaskPriorityName($task->getPriority()));
 
-    $handles = $this->getLoadedHandles();
-    $cc_handles = array_select_keys($handles, $task->getCCPHIDs());
-    $subscriber_html = id(new SubscriptionListStringBuilder())
-      ->setObjectPHID($task->getPHID())
-      ->setHandles($cc_handles)
-      ->buildPropertyString();
-    $view->addProperty(pht('Subscribers'), $subscriber_html);
-
     $view->addProperty(
       pht('Author'),
       $this->getHandle($task->getAuthorPHID())->renderLink());
diff --git a/src/applications/maniphest/controller/ManiphestTaskEditController.php b/src/applications/maniphest/controller/ManiphestTaskEditController.php
--- a/src/applications/maniphest/controller/ManiphestTaskEditController.php
+++ b/src/applications/maniphest/controller/ManiphestTaskEditController.php
@@ -38,6 +38,7 @@
             PhabricatorPolicyCapability::CAN_EDIT,
           ))
         ->withIDs(array($this->id))
+        ->needSubscriberPHIDs(true)
         ->executeOne();
       if (!$task) {
         return new Aphront404Response();
@@ -215,7 +216,7 @@
         $task->setDescription($new_desc);
         $task->setPriority($request->getInt('priority'));
         $task->setOwnerPHID($owner_phid);
-        $task->setCCPHIDs($request->getArr('cc'));
+        $task->attachSubscriberPHIDs($request->getArr('cc'));
         $task->attachProjectPHIDs($request->getArr('projects'));
       } else {
 
@@ -227,7 +228,8 @@
           $changes[ManiphestTransaction::TYPE_OWNER] = $owner_phid;
         }
 
-        $changes[ManiphestTransaction::TYPE_CCS] = $request->getArr('cc');
+        $changes[PhabricatorTransactions::TYPE_SUBSCRIBERS] =
+          array('=' => $request->getArr('cc'));
 
         if ($can_edit_projects) {
           $projects = $request->getArr('projects');
@@ -436,19 +438,20 @@
       }
     } else {
       if (!$task->getID()) {
-        $task->setCCPHIDs(array(
+        $task->attachSubscriberPHIDs(array(
           $user->getPHID(),
         ));
         if ($template_id) {
           $template_task = id(new ManiphestTaskQuery())
             ->setViewer($user)
             ->withIDs(array($template_id))
+            ->needSubscriberPHIDs(true)
             ->executeOne();
           if ($template_task) {
             $cc_phids = array_unique(array_merge(
-              $template_task->getCCPHIDs(),
+              $template_task->getSubscriberPHIDs(),
               array($user->getPHID())));
-            $task->setCCPHIDs($cc_phids);
+            $task->attachSubscriberPHIDs($cc_phids);
             $task->attachProjectPHIDs($template_task->getProjectPHIDs());
             $task->setOwnerPHID($template_task->getOwnerPHID());
             $task->setPriority($template_task->getPriority());
@@ -486,7 +489,7 @@
 
     $phids = array_merge(
       array($task->getOwnerPHID()),
-      $task->getCCPHIDs(),
+      $task->getSubscriberPHIDs(),
       $task->getProjectPHIDs());
 
     if ($parent_task) {
@@ -512,8 +515,8 @@
       $assigned_value = array();
     }
 
-    if ($task->getCCPHIDs()) {
-      $cc_value = array_select_keys($handles, $task->getCCPHIDs());
+    if ($task->getSubscriberPHIDs()) {
+      $cc_value = array_select_keys($handles, $task->getSubscriberPHIDs());
     } else {
       $cc_value = array();
     }
diff --git a/src/applications/maniphest/controller/ManiphestTransactionPreviewController.php b/src/applications/maniphest/controller/ManiphestTransactionPreviewController.php
--- a/src/applications/maniphest/controller/ManiphestTransactionPreviewController.php
+++ b/src/applications/maniphest/controller/ManiphestTransactionPreviewController.php
@@ -58,22 +58,19 @@
         }
         $transaction->setNewValue($value);
         break;
-      case ManiphestTransaction::TYPE_CCS:
+      case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         if ($value) {
           $value = json_decode($value);
         }
         if (!$value) {
           $value = array();
         }
-        $phids = $value;
-
-        foreach ($task->getCCPHIDs() as $cc_phid) {
+        $phids = array();
+        foreach ($value as $cc_phid) {
           $phids[] = $cc_phid;
-          $value[] = $cc_phid;
         }
-
-        $transaction->setOldValue($task->getCCPHIDs());
-        $transaction->setNewValue($value);
+        $transaction->setOldValue(array());
+        $transaction->setNewValue($phids);
         break;
       case ManiphestTransaction::TYPE_PROJECTS:
         if ($value) {
diff --git a/src/applications/maniphest/controller/ManiphestTransactionSaveController.php b/src/applications/maniphest/controller/ManiphestTransactionSaveController.php
--- a/src/applications/maniphest/controller/ManiphestTransactionSaveController.php
+++ b/src/applications/maniphest/controller/ManiphestTransactionSaveController.php
@@ -9,6 +9,7 @@
     $task = id(new ManiphestTaskQuery())
       ->setViewer($user)
       ->withIDs(array($request->getStr('taskID')))
+      ->needSubscriberPHIDs(true)
       ->executeOne();
     if (!$task) {
       return new Aphront404Response();
@@ -33,7 +34,7 @@
 
     $cc_transaction = new ManiphestTransaction();
     $cc_transaction
-      ->setTransactionType(ManiphestTransaction::TYPE_CCS);
+      ->setTransactionType(PhabricatorTransactions::TYPE_SUBSCRIBERS);
 
     $transaction = new ManiphestTransaction();
     $transaction
@@ -64,7 +65,7 @@
               '+' => array_fuse($projects),
             ));
         break;
-      case ManiphestTransaction::TYPE_CCS:
+      case PhabricatorTransactions::TYPE_SUBSCRIBERS:
         // Accumulate the new explicit CCs into the array that we'll add in
         // the CC transaction later.
         $added_ccs = array_merge($added_ccs, $request->getArr('ccs'));
@@ -135,19 +136,21 @@
     if (!$user_owns_task) {
       // If we aren't making the user the new task owner and they aren't the
       // existing task owner, add them to CC unless they're aleady CC'd.
-      if (!in_array($user->getPHID(), $task->getCCPHIDs())) {
+      if (!in_array($user->getPHID(), $task->getSubscriberPHIDs())) {
         $added_ccs[] = $user->getPHID();
       }
     }
 
     // Evade no-effect detection in the new editor stuff until we can switch
     // to subscriptions.
-    $added_ccs = array_filter(array_diff($added_ccs, $task->getCCPHIDs()));
+    $added_ccs = array_filter(array_diff(
+      $added_ccs,
+      $task->getSubscriberPHIDs()));
 
     if ($added_ccs) {
       // We've added CCs, so include a CC transaction.
-      $all_ccs = array_merge($task->getCCPHIDs(), $added_ccs);
-      $cc_transaction->setNewValue($all_ccs);
+      $all_ccs = array_merge($task->getSubscriberPHIDs(), $added_ccs);
+      $cc_transaction->setNewValue(array('=' => $all_ccs));
       $transactions[] = $cc_transaction;
     }
 
diff --git a/src/applications/maniphest/editor/ManiphestTransactionEditor.php b/src/applications/maniphest/editor/ManiphestTransactionEditor.php
--- a/src/applications/maniphest/editor/ManiphestTransactionEditor.php
+++ b/src/applications/maniphest/editor/ManiphestTransactionEditor.php
@@ -23,7 +23,6 @@
     $types[] = ManiphestTransaction::TYPE_TITLE;
     $types[] = ManiphestTransaction::TYPE_DESCRIPTION;
     $types[] = ManiphestTransaction::TYPE_OWNER;
-    $types[] = ManiphestTransaction::TYPE_CCS;
     $types[] = ManiphestTransaction::TYPE_SUBPRIORITY;
     $types[] = ManiphestTransaction::TYPE_PROJECT_COLUMN;
     $types[] = ManiphestTransaction::TYPE_MERGED_INTO;
@@ -62,8 +61,6 @@
         return $object->getDescription();
       case ManiphestTransaction::TYPE_OWNER:
         return nonempty($object->getOwnerPHID(), null);
-      case ManiphestTransaction::TYPE_CCS:
-        return array_values(array_unique($object->getCCPHIDs()));
       case ManiphestTransaction::TYPE_PROJECT_COLUMN:
         // These are pre-populated.
         return $xaction->getOldValue();
@@ -82,8 +79,6 @@
     switch ($xaction->getTransactionType()) {
       case ManiphestTransaction::TYPE_PRIORITY:
         return (int)$xaction->getNewValue();
-      case ManiphestTransaction::TYPE_CCS:
-        return array_values(array_unique($xaction->getNewValue()));
       case ManiphestTransaction::TYPE_OWNER:
         return nonempty($xaction->getNewValue(), null);
       case ManiphestTransaction::TYPE_STATUS:
@@ -106,10 +101,6 @@
     $new = $xaction->getNewValue();
 
     switch ($xaction->getTransactionType()) {
-      case ManiphestTransaction::TYPE_CCS:
-        sort($old);
-        sort($new);
-        return ($old !== $new);
       case ManiphestTransaction::TYPE_PROJECT_COLUMN:
         $new_column_phids = $new['columnPHIDs'];
         $old_column_phids = $old['columnPHIDs'];
@@ -155,8 +146,6 @@
         }
 
         return $object->setOwnerPHID($phid);
-      case ManiphestTransaction::TYPE_CCS:
-        return $object->setCCPHIDs($xaction->getNewValue());
       case ManiphestTransaction::TYPE_SUBPRIORITY:
         $data = $xaction->getNewValue();
         $new_sub = $this->getNextSubpriority(
@@ -433,10 +422,6 @@
   protected function getMailCC(PhabricatorLiskDAO $object) {
     $phids = array();
 
-    foreach ($object->getCCPHIDs() as $phid) {
-      $phids[] = $phid;
-    }
-
     foreach (parent::getMailCC($object) as $phid) {
       $phids[] = $phid;
     }
@@ -561,22 +546,16 @@
     HeraldAdapter $adapter,
     HeraldTranscript $transcript) {
 
-    // TODO: Convert these to transactions. The way Maniphest deals with these
-    // transactions is currently unconventional and messy.
+    $this->heraldEmailPHIDs = $adapter->getEmailPHIDs();
+    $xactions = array();
 
-    $save_again = false;
     $cc_phids = $adapter->getCcPHIDs();
     if ($cc_phids) {
-      $existing_cc = $object->getCCPHIDs();
-      $new_cc = array_unique(array_merge($cc_phids, $existing_cc));
-      $object->setCCPHIDs($new_cc);
-      $object->save();
+      $xactions[] = id(new ManiphestTransaction())
+        ->setTransactionType(PhabricatorTransactions::TYPE_SUBSCRIBERS)
+        ->setNewValue(array('+' => $cc_phids));
     }
 
-    $this->heraldEmailPHIDs = $adapter->getEmailPHIDs();
-
-    $xactions = array();
-
     $assign_phid = $adapter->getAssignPHID();
     if ($assign_phid) {
       $xactions[] = id(new ManiphestTransaction())
diff --git a/src/applications/maniphest/lipsum/PhabricatorManiphestTaskTestDataGenerator.php b/src/applications/maniphest/lipsum/PhabricatorManiphestTaskTestDataGenerator.php
--- a/src/applications/maniphest/lipsum/PhabricatorManiphestTaskTestDataGenerator.php
+++ b/src/applications/maniphest/lipsum/PhabricatorManiphestTaskTestDataGenerator.php
@@ -28,8 +28,8 @@
       $this->generateTaskStatus();
     $changes[ManiphestTransaction::TYPE_PRIORITY] =
       $this->generateTaskPriority();
-    $changes[ManiphestTransaction::TYPE_CCS] =
-      $this->getCCPHIDs();
+    $changes[PhabricatorTransactions::TYPE_SUBSCRIBERS] =
+      array('=' => $this->getCCPHIDs());
     $transactions = array();
     foreach ($changes as $type => $value) {
       $transaction = clone $template;
diff --git a/src/applications/maniphest/mail/ManiphestReplyHandler.php b/src/applications/maniphest/mail/ManiphestReplyHandler.php
--- a/src/applications/maniphest/mail/ManiphestReplyHandler.php
+++ b/src/applications/maniphest/mail/ManiphestReplyHandler.php
@@ -106,14 +106,14 @@
           break;
         case 'unsubscribe':
           $is_unsub = true;
-          $ttype = ManiphestTransaction::TYPE_CCS;
-          $ccs = $task->getCCPHIDs();
+          $ttype = PhabricatorTransactions::TYPE_SUBSCRIBERS;
+          $ccs = $task->getSubscriberPHIDs();
           foreach ($ccs as $k => $phid) {
             if ($phid == $user->getPHID()) {
               unset($ccs[$k]);
             }
           }
-          $new_value = array_values($ccs);
+          $new_value = array('=' => array_values($ccs));
           break;
       }
 
@@ -135,7 +135,7 @@
     }
 
     $ccs = $mail->loadCCPHIDs();
-    $old_ccs = $task->getCCPHIDs();
+    $old_ccs = $task->getSubscriberPHIDs();
     $new_ccs = array_merge($old_ccs, $ccs);
     if (!$is_unsub) {
       $new_ccs[] = $user->getPHID();
@@ -144,8 +144,9 @@
 
     if (array_diff($new_ccs, $old_ccs)) {
       $cc_xaction = clone $template;
-      $cc_xaction->setTransactionType(ManiphestTransaction::TYPE_CCS);
-      $cc_xaction->setNewValue($new_ccs);
+      $cc_xaction->setTransactionType(
+        PhabricatorTransactions::TYPE_SUBSCRIBERS);
+      $cc_xaction->setNewValue(array('=' => $new_ccs));
       $xactions[] = $cc_xaction;
     }
 
diff --git a/src/applications/maniphest/mail/ManiphestTaskMailReceiver.php b/src/applications/maniphest/mail/ManiphestTaskMailReceiver.php
--- a/src/applications/maniphest/mail/ManiphestTaskMailReceiver.php
+++ b/src/applications/maniphest/mail/ManiphestTaskMailReceiver.php
@@ -17,6 +17,7 @@
     $results = id(new ManiphestTaskQuery())
       ->setViewer($viewer)
       ->withIDs(array($id))
+      ->needSubscriberPHIDs(true)
       ->execute();
 
     return head($results);
diff --git a/src/applications/maniphest/query/ManiphestTaskQuery.php b/src/applications/maniphest/query/ManiphestTaskQuery.php
--- a/src/applications/maniphest/query/ManiphestTaskQuery.php
+++ b/src/applications/maniphest/query/ManiphestTaskQuery.php
@@ -50,6 +50,8 @@
   const ORDER_MODIFIED      = 'order-modified';
   const ORDER_TITLE         = 'order-title';
 
+  private $needSubscriberPHIDs;
+
   const DEFAULT_PAGE_SIZE   = 1000;
 
   public function withAuthors(array $authors) {
@@ -178,6 +180,11 @@
     return $this;
   }
 
+  public function needSubscriberPHIDs($bool) {
+    $this->needSubscriberPHIDs = $bool;
+    return $this;
+  }
+
   public function loadPage() {
     // TODO: (T603) It is possible for a user to find the PHID of a project
     // they can't see, then query for tasks in that project and deduce the
@@ -196,7 +203,6 @@
     $where[] = $this->buildPrioritiesWhereClause($conn);
     $where[] = $this->buildAuthorWhereClause($conn);
     $where[] = $this->buildOwnerWhereClause($conn);
-    $where[] = $this->buildSubscriberWhereClause($conn);
     $where[] = $this->buildProjectWhereClause($conn);
     $where[] = $this->buildAnyProjectWhereClause($conn);
     $where[] = $this->buildAnyUserProjectWhereClause($conn);
@@ -332,12 +338,14 @@
   }
 
   protected function didFilterPage(array $tasks) {
+    $phids = mpull($tasks, 'getPHID');
+
     // TODO: Eventually, we should make this optional and introduce a
     // needProjectPHIDs() method, but for now there's a lot of code which
     // assumes the data is always populated.
 
     $edge_query = id(new PhabricatorEdgeQuery())
-      ->withSourcePHIDs(mpull($tasks, 'getPHID'))
+      ->withSourcePHIDs($phids)
       ->withEdgeTypes(
         array(
           PhabricatorProjectObjectHasProjectEdgeType::EDGECONST,
@@ -345,8 +353,19 @@
     $edge_query->execute();
 
     foreach ($tasks as $task) {
-      $phids = $edge_query->getDestinationPHIDs(array($task->getPHID()));
-      $task->attachProjectPHIDs($phids);
+      $project_phids = $edge_query->getDestinationPHIDs(
+        array($task->getPHID()));
+      $task->attachProjectPHIDs($project_phids);
+    }
+
+    if ($this->needSubscriberPHIDs) {
+      $subscriber_sets = id(new PhabricatorSubscribersQuery())
+        ->withObjectPHIDs($phids)
+        ->execute();
+      foreach ($tasks as $task) {
+        $subscribers = idx($subscriber_sets, $task->getPHID(), array());
+        $task->attachSubscriberPHIDs($subscribers);
+      }
     }
 
     return $tasks;
@@ -497,17 +516,6 @@
       $fulltext_results);
   }
 
-  private function buildSubscriberWhereClause(AphrontDatabaseConnection $conn) {
-    if (!$this->subscriberPHIDs) {
-      return null;
-    }
-
-    return qsprintf(
-      $conn,
-      'subscriber.subscriberPHID IN (%Ls)',
-      $this->subscriberPHIDs);
-  }
-
   private function buildProjectWhereClause(AphrontDatabaseConnection $conn) {
     if (!$this->projectPHIDs && !$this->includeNoProject) {
       return null;
@@ -708,11 +716,14 @@
     }
 
     if ($this->subscriberPHIDs) {
-      $subscriber_dao = new ManiphestTaskSubscriber();
       $joins[] = qsprintf(
         $conn_r,
-        'JOIN %T subscriber ON subscriber.taskPHID = task.phid',
-        $subscriber_dao->getTableName());
+        'JOIN %T e_ccs ON e_ccs.src = task.phid '.
+        'AND e_ccs.type = %s '.
+        'AND e_ccs.dst in (%Ls)',
+        PhabricatorEdgeConfig::TABLE_NAME_EDGE,
+        PhabricatorEdgeConfig::TYPE_OBJECT_HAS_SUBSCRIBER,
+        $this->subscriberPHIDs);
     }
 
     switch ($this->groupBy) {
diff --git a/src/applications/maniphest/search/ManiphestSearchIndexer.php b/src/applications/maniphest/search/ManiphestSearchIndexer.php
--- a/src/applications/maniphest/search/ManiphestSearchIndexer.php
+++ b/src/applications/maniphest/search/ManiphestSearchIndexer.php
@@ -54,21 +54,6 @@
         $task->getDateCreated());
     }
 
-    // We need to load handles here since non-users may subscribe (mailing
-    // lists, e.g.)
-    $ccs = $task->getCCPHIDs();
-    $handles = id(new PhabricatorHandleQuery())
-      ->setViewer(PhabricatorUser::getOmnipotentUser())
-      ->withPHIDs($ccs)
-      ->execute();
-    foreach ($ccs as $cc) {
-      $doc->addRelationship(
-        PhabricatorSearchRelationship::RELATIONSHIP_SUBSCRIBER,
-        $handles[$cc]->getPHID(),
-        $handles[$cc]->getType(),
-        time());
-    }
-
     return $doc;
   }
 
diff --git a/src/applications/maniphest/storage/ManiphestTask.php b/src/applications/maniphest/storage/ManiphestTask.php
--- a/src/applications/maniphest/storage/ManiphestTask.php
+++ b/src/applications/maniphest/storage/ManiphestTask.php
@@ -2,6 +2,7 @@
 
 final class ManiphestTask extends ManiphestDAO
   implements
+    PhabricatorSubscribableInterface,
     PhabricatorMarkupInterface,
     PhabricatorPolicyInterface,
     PhabricatorTokenReceiverInterface,
@@ -17,7 +18,6 @@
 
   protected $authorPHID;
   protected $ownerPHID;
-  protected $ccPHIDs = array();
 
   protected $status;
   protected $priority;
@@ -33,10 +33,10 @@
 
   protected $attached = array();
   protected $projectPHIDs = array();
-  private $subscribersNeedUpdate;
 
   protected $ownerOrdering;
 
+  private $subscriberPHIDs = self::ATTACHABLE;
   private $groupByProjectPHID = self::ATTACHABLE;
   private $customFields = self::ATTACHABLE;
   private $edgeProjectPHIDs = self::ATTACHABLE;
@@ -56,7 +56,8 @@
       ->setAuthorPHID($actor->getPHID())
       ->setViewPolicy($view_policy)
       ->setEditPolicy($edit_policy)
-      ->attachProjectPHIDs(array());
+      ->attachProjectPHIDs(array())
+      ->attachSubscriberPHIDs(array());
   }
 
   public function getConfiguration() {
@@ -141,8 +142,8 @@
     return PhabricatorPHID::generateNewPHID(ManiphestTaskPHIDType::TYPECONST);
   }
 
-  public function getCCPHIDs() {
-    return array_values(nonempty($this->ccPHIDs, array()));
+  public function getSubscriberPHIDs() {
+    return $this->assertAttached($this->subscriberPHIDs);
   }
 
   public function getProjectPHIDs() {
@@ -154,15 +155,13 @@
     return $this;
   }
 
-  public function setCCPHIDs(array $phids) {
-    $this->ccPHIDs = array_values($phids);
-    $this->subscribersNeedUpdate = true;
+  public function attachSubscriberPHIDs(array $phids) {
+    $this->subscriberPHIDs = $phids;
     return $this;
   }
 
   public function setOwnerPHID($phid) {
     $this->ownerPHID = nonempty($phid, null);
-    $this->subscribersNeedUpdate = true;
     return $this;
   }
 
@@ -194,13 +193,6 @@
 
     $result = parent::save();
 
-    if ($this->subscribersNeedUpdate) {
-      // If we've changed the subscriber PHIDs for this task, update the link
-      // table.
-      ManiphestTaskSubscriber::updateTaskSubscribers($this);
-      $this->subscribersNeedUpdate = false;
-    }
-
     return $result;
   }
 
@@ -217,6 +209,22 @@
   }
 
 
+/* -(  PhabricatorSubscribableInterface  )----------------------------------- */
+
+
+  public function isAutomaticallySubscribed($phid) {
+    return ($phid == $this->getOwnerPHID());
+  }
+
+  public function shouldShowSubscribersProperty() {
+    return true;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return true;
+  }
+
+
 /* -(  Markup Interface  )--------------------------------------------------- */
 
 
diff --git a/src/applications/maniphest/storage/ManiphestTaskSubscriber.php b/src/applications/maniphest/storage/ManiphestTaskSubscriber.php
--- a/src/applications/maniphest/storage/ManiphestTaskSubscriber.php
+++ b/src/applications/maniphest/storage/ManiphestTaskSubscriber.php
@@ -1,5 +1,8 @@
 <?php
 
+/**
+ * Deprecated; delete me.
+ */
 final class ManiphestTaskSubscriber extends ManiphestDAO {
 
   protected $taskPHID;
diff --git a/src/applications/maniphest/storage/ManiphestTransaction.php b/src/applications/maniphest/storage/ManiphestTransaction.php
--- a/src/applications/maniphest/storage/ManiphestTransaction.php
+++ b/src/applications/maniphest/storage/ManiphestTransaction.php
@@ -7,7 +7,6 @@
   const TYPE_STATUS = 'status';
   const TYPE_DESCRIPTION = 'description';
   const TYPE_OWNER  = 'reassign';
-  const TYPE_CCS = 'ccs';
   const TYPE_PROJECTS = 'projects';
   const TYPE_PRIORITY = 'priority';
   const TYPE_EDGE = 'edge';
@@ -21,6 +20,12 @@
   // NOTE: this type is deprecated. Keep it around for legacy installs
   // so any transactions render correctly.
   const TYPE_ATTACH = 'attach';
+  /**
+   * TYPE_CCS is legacy and depracted in favor of
+   * PhabricatorTransactions::TYPE_SUBSCRIBERS; keep it around for legacy
+   * transaction-rendering.
+   */
+  const TYPE_CCS = 'ccs';
 
 
   const MAILTAG_STATUS = 'maniphest-status';
diff --git a/src/applications/search/controller/PhabricatorSearchAttachController.php b/src/applications/search/controller/PhabricatorSearchAttachController.php
--- a/src/applications/search/controller/PhabricatorSearchAttachController.php
+++ b/src/applications/search/controller/PhabricatorSearchAttachController.php
@@ -143,6 +143,7 @@
     $targets = id(new ManiphestTaskQuery())
       ->setViewer($user)
       ->withPHIDs(array_keys($phids))
+      ->needSubscriberPHIDs(true)
       ->execute();
 
     if (empty($targets)) {
@@ -156,9 +157,13 @@
       ->setContinueOnMissingFields(true);
 
     $cc_vector = array();
-    $cc_vector[] = $task->getCCPHIDs();
+    // since we loaded this via a generic object query, go ahead and get the
+    // attach the cc phids now
+    $task->attachSubscriberPHIDs(
+      PhabricatorSubscribersQuery::loadSubscribersForPHID($task->getPHID()));
+    $cc_vector[] = $task->getSubscriberPHIDs();
     foreach ($targets as $target) {
-      $cc_vector[] = $target->getCCPHIDs();
+      $cc_vector[] = $target->getSubscriberPHIDs();
       $cc_vector[] = array(
         $target->getAuthorPHID(),
         $target->getOwnerPHID(),
@@ -178,8 +183,8 @@
     $all_ccs = array_unique($all_ccs);
 
     $add_ccs = id(new ManiphestTransaction())
-      ->setTransactionType(ManiphestTransaction::TYPE_CCS)
-      ->setNewValue($all_ccs);
+      ->setTransactionType(PhabricatorTransactions::TYPE_SUBSCRIBERS)
+      ->setNewValue(array('=' => $all_ccs));
 
     $merged_from_txn = id(new ManiphestTransaction())
       ->setTransactionType(ManiphestTransaction::TYPE_MERGED_FROM)
diff --git a/src/applications/subscriptions/controller/PhabricatorSubscriptionsListController.php b/src/applications/subscriptions/controller/PhabricatorSubscriptionsListController.php
--- a/src/applications/subscriptions/controller/PhabricatorSubscriptionsListController.php
+++ b/src/applications/subscriptions/controller/PhabricatorSubscriptionsListController.php
@@ -23,8 +23,6 @@
     if ($object instanceof PhabricatorSubscribableInterface) {
       $subscriber_phids = PhabricatorSubscribersQuery::loadSubscribersForPHID(
         $phid);
-    } else if ($object instanceof ManiphestTask) {
-      $subscriber_phids = $object->getCCPHIDs();
     }
 
     $handle_phids = $subscriber_phids;