Well, your sisters or wife or dad could repost something you posted and then it's only as secure as their settings. Also, if you are both tagged in a picture t

Well, your sisters or wife or dad could repost something you posted and then it's only as secure as their settings. Also, if you are both tagged in a picture then all of your friends' friends can see the picture of you if your friend lets them. And, if someone finds an old embarrassing picture of you they can just upload it to Facebook and tag you and all of their friends (yours if you share mutual friends) are notified and can look at it until you get a chance to un-tag yourself.