It depends on what they do.
Facebook, Stardoll, Moviestarplanet, Popgirlworld...
it is good for their body
For conclusion the facebook is an good network site
Not all teenagers are bad
there are quiet allot of teenagers that use facebook and it is impossible to count every teenage user on facebook that would be like counting strings of hay.
Facebook is good for teens because they can have fun, talk to their friends, get in touch with people they can't get in touch with and Scientists have proven that Facebook, and other online sites actually help develop social skills for teens!
well it can be good but it also can be bad.
It can be but not always cause it depends on what you do.
it depends on how you use it
No it is very good!
There must be Millions of teenagers using facebook.
There aren't really good or bad effects of facebook , because facebook is great website. Unless the person had bad effects on it. Its good cause you can meet people around the word or share things with your friends , play games and enjoy much more.