I don't really think they should lower the age restrictions even though some may say there are already some kids under 13. If they lowered it. It gives the idea that it is safe for young children but in my experience it isn't. Cyberbullying runs rampant on the Internet and Facebook, being a social networking site is filled with this. No parent can constantly moderator their children's activity and being a young child means they could get easier hurt.
Honestly it doesn't make a difference because of how simple it is now becoming to create an account and without a doubt there are under 13's with a fake account. kids may have older friends and family who encourage them to use it. also, trying to prevent something from going public makes it go public and I would like to employ reverse psychology by maybe lowering the age limit to see what happens. Also, these sites provide a great way to communicate with friends and family across long distances.
Well the why I saw it. It creates the illusion to parents that Facebook is a safe place for children and there are ways for parents to block Facebook for their children to use it. So, its not that easy if parents are informed. The question is if they lower the age they may not even question if it is truly safe. Reverse psychology does work in some cases but if you tell your kid it is okay to eat a cookie they'll eat it , if you catch my drift. Phones work the same but you know everyone on it.