diff --git a/src/applications/conpherence/query/ConpherenceThreadQuery.php b/src/applications/conpherence/query/ConpherenceThreadQuery.php
--- a/src/applications/conpherence/query/ConpherenceThreadQuery.php
+++ b/src/applications/conpherence/query/ConpherenceThreadQuery.php
@@ -136,7 +136,7 @@
 
   protected function buildGroupClause(AphrontDatabaseConnection $conn_r) {
     if ($this->participantPHIDs !== null || strlen($this->fulltext)) {
-      return 'GROUP BY thread.id';
+      return qsprintf($conn_r, 'GROUP BY thread.id');
     } else {
       return $this->buildApplicationSearchGroupClause($conn_r);
     }
@@ -192,18 +192,24 @@
     if ($can_optimize) {
       $members_policy = id(new ConpherenceThreadMembersPolicyRule())
         ->getObjectPolicyFullKey();
+      $policies = array(
+        $members_policy,
+        PhabricatorPolicies::POLICY_USER,
+        PhabricatorPolicies::POLICY_ADMIN,
+        PhabricatorPolicies::POLICY_NOONE,
+      );
 
       if ($viewer->isLoggedIn()) {
         $where[] = qsprintf(
           $conn,
-          'thread.viewPolicy != %s OR vp.participantPHID = %s',
-          $members_policy,
+          'thread.viewPolicy NOT IN (%Ls) OR vp.participantPHID = %s',
+          $policies,
           $viewer->getPHID());
       } else {
         $where[] = qsprintf(
           $conn,
-          'thread.viewPolicy != %s',
-          $members_policy);
+          'thread.viewPolicy NOT IN (%Ls)',
+          $policies);
       }
     }
 
diff --git a/src/applications/conpherence/view/ConpherenceLayoutView.php b/src/applications/conpherence/view/ConpherenceLayoutView.php
--- a/src/applications/conpherence/view/ConpherenceLayoutView.php
+++ b/src/applications/conpherence/view/ConpherenceLayoutView.php
@@ -224,12 +224,12 @@
   private function buildNUXView() {
     $viewer = $this->getViewer();
 
-    $engine = new ConpherenceThreadSearchEngine();
-    $engine->setViewer($viewer);
+    $engine = id(new ConpherenceThreadSearchEngine())
+      ->setViewer($viewer);
     $saved = $engine->buildSavedQueryFromBuiltin('all');
     $query = $engine->buildQueryFromSavedQuery($saved);
-    $pager = $engine->newPagerForSavedQuery($saved);
-    $pager->setPageSize(10);
+    $pager = $engine->newPagerForSavedQuery($saved)
+      ->setPageSize(10);
     $results = $engine->executeQuery($query, $pager);
     $view = $engine->renderResults($results, $saved);