Comment 1 for bug 1429505

A couple more options:

4. Same as #1 (remove the page from the watchlist when you lose access to it), but we also send the watcher a notification message that says "Page X on your watchlist, has been deleted or is no longer visible to you."

5. We retain the record for the page on their watchlist, but we simply hide the page from displaying on the watchlist block, and we don't send them any notifications about it. This solution has the advantage that, if the page becomes accessible to them again, it re-appears on their watchlist.

6. The same as #5, but with notifications to say "Page X you were watching has been deleted or is no longer visible to you" when the page goes away, and another notification to say, "Page X you were watching and which you lost access to, is now visible to you again."

I think I favor option #5 (just make the inaccessible watched page invisible), but... for technical reasons it might be tricky to implement it along with paginating the watchlist block. We'd have to incorporate the access control calculations into the paginated SQL!

I also think that we should implement option #3 at some point.