It's almost a clever idea, but what FB really does is show you pictures that have been TAGGED as your friends, when in reality it's up to whomever tagged them to be correct. And I've seen plenty of pictures of woodland animals, circus and carnival performers and other less respectable items tagged as my friends when they clearly are not. So, it can be worse than secret questions when you try to create an account somewhere and the secret question is "who is this?" and the picture is of a horse in heat doing what nature dictates.