Children on Facebook should have their pages monitored by parents. Children always think they are more mature and understanding on the world than what they are, and Facebook is a way that they can easily put themselves in danger by speaking with people they shouldn't be or even just saying things they shouldn't be saying.
This isn't a shot at Facebook at all. As a matter of fact, Facebook seems to be among the safest of social networking sites. With that said, children are never safe on the Internet. It's too easy to fall for traps, and there are a lot of cunning people with bad intentions out there.
Kids can get cyber bullied on Facebook. The parents should check their sons' and daughters' Facebook, because their feelings can get hurt. If they become friends with somebody they don't know and if that person gives you their address there could be trouble. The person might want to hurt you. This is why kids aren't safe on Facebook.
Kids don't need social networking. Our generation didn't have it until around the time we were getting old enough to make responsible (or less irresponsible) decisions, and most of us would have gotten into trouble if we had it earlier. I would have. Children shouldn't be on Facebook and Facebook should be making a very sincere effort to ensure that they aren't.
Children should be focused on the world in their neighborhood, not on the global world. They are really just learning how to interact socially, and it is best if they learn how to have one on one interactions or interactions with people in their own community first. They need to build up the social skills that allows them to discriminate between sincerity and insincerity, honesty and dishonesty, spitefulness and all the other social interactions before they go public. I see Facebook as a largely friendly place, but you have to know human nature before you can be sure you are safe.