When viewing the tree underneath a Phriction document, you can see children you don't have permission to view.
This is a holdover from long ago, but we should probably lock it down for consistency. One quick fix would be to pull all the handles after loading the documents and then use the handles to render the links, so we get "Restricted Document" for the ones you can't see.
A more complex fix would be to turn the ad-hoc hierarchical query into a real Query but I don't think this gets us anything today.