What Anonymous should do is claim they are ready to do this and give everybody a couple days notice to remove their accounts before the hit. lulz would ensue if they could get the media worked up, which I bet wouldn't be that hard to do.
Part of the algorithm may involve them trying to predict who you will want to add as a friend. People that attended the same events as you, people who have recently added your friends as friends, stuff like that.
Would it be possible for somebody to create a virus that would grab this file and publish it to people's profiles? I think I'd crawl into a hole and die if my ex girlfriend discovered how highly she ranked...