They can and do get out, and ruin lives in the process—especially if a kid does it themselves. This is a terrible story from our own backyard: Facebook stalker gets girl to give him naked pics, and then blackmails her and a friend for more.
The darker side of social media is maturing, so to speak, and the old methods of extortion, blackmail, stalking, and sexual harassment have become recognizable patterns. Kids are new to everything, so even if you know never to friend someone you’ve never heard of, your child doesn’t.
Molesters are invariably good at manipulating children—it’s all they think about and all the practice. Always monitor your kids’ internet use by making them give you their password. It’s “invasive”? Tough. Child abusers are evil incarnate, and they count on the “discretion” and “politeness” of society to keep their predations secret. Be nosy. The life you save may be your child’s. Still, evil people do evil things, and the best we can do as parents is try to keep our kids safe.
As for this poor girl and her friend, if they ever find this piece of filth who is blackmailing them, I hope they get a chance to use Masha’s law and bankrupt the creep.