Part of why I personally believe it is I've seen how Facebook really doesn't want people making fake accounts. I had a Facebook account and was friends with like, 2, family members, never really used it. Somehow Facebook decided they needed to see a photo of my drivers license to let me use the account. Nope. I decided to consider this a feature, and there has been a time or two over the last several years where that persistent requirement for a drivers license to unlock my account has kept me from giving in to peer pressure. Facebook has helped me avoid using Facebook. It has been to my advantage.