Here they run a commercial. A youngish (late twenties) man approaches a girl (15?), at first striking up conversation, then getting a little creepy with the attention, asking whether they can be "friends." She leaves, obviously creeped out (as I was when I first saw it). Next she is approached by a guy who asks what color underwear she is wearing. And it goes on. Then at the end the commercial reveals its point, that when you post on cyberspace (on a private outlet is bad enough, but on a PUBLIC forum), you will make more friends than you want.
Personally, I've told my sons they are not getting a phone until their 16 (when they get their license: then they had better have it on them at all times).
As these children (and that's what they are) aren't thinking, what are their parents thinking when they get them the easy access that can't be supervised.