They actually did a writeup on their photo storage system a while ago: http://www.facebook.com/note.php?note_id=76191543919 http://www.facebook.com/note.php?not

They actually did a writeup on their photo storage system a while ago: http://www.facebook.com/note.php?note_id=76191543919 http://www.facebook.com/note.php?note_id=76191543919 Note that the delete operation merely marks the data deleted - they don't actually purge or overwrite it. Perhaps there's some kind of bug in this deleted-marking system? Kind of weird they haven't been able to fix it yet though.