Myspace can be dangerous, but not facebook. :) When te make your account, te don’t have to put your phone number down, o where te live o anything that te do not feel comfortable with sharing. Also, for any one to even become your friend (meaning te let that person talk to te and see your page) te have to OK them as your friend. Hope this helped :)
Facebook is not dangerous. People say its like myspace, but its a lot safer than myspace. myspace is a lot worse than facebook. (im allowed to have a Facebook but not a myspace)
Facebook is only as sicuro, cassetta di sicurezza as te make it. Adjust your privacy settings accordingly, and block people if necessary. I can't speak personally on MySpace, as I don't use it. Remember, Enjoy Yourself ;-)