Privacy used to be enforced by inconvenience; you couldn't just spy on anyone you wanted. Increasingly, though, privacy will have to be enforced by us grownups simply choosing not to look, since it's none of our business.
This discipline isn't just to protect them, it's to protect us. If you're considering a job applicant, and he has some louche photos on the Web, he has a problem. But if one applicant in 10 has similar pictures online, then you've got a problem, because you'll be at a competitive disadvantage for talent, relative to firms that don't spy.
People my age tut-tut at kids, telling them that we wouldn't have put those photos up when we were young, but we're lying. We'd have done it in a heartbeat, but no one ever offered us the chance.