A.B.
Our son is a high school freshman and he has destroyed whatever right to privacy he had, by doing things online that were reckless and outright dangerous. He posted on Instagram provocative photos of himself shirtless and tagged the photos with sexual terms like #gayteen. He met male strangers online and gave them his phone number or text address. He got into arguments with strangers on Facebook where he was verbally abusive.
I love our son and he is a great kid overall, but his brain simply is not mature enough for the awesome challenge of using the Internet responsibly. As a result, we monitor his computer with a program that let's us know what he is doing online. We took away his smartphone, because he can do a lot less damage with a flip phone. (No Instagram! No Kik! Heck, no Internet!)
I felt bad at first for "spying" on him, but he knows we are monitoring him and, as his therapist said, safety trumps privacy any day.
I suspect people will disagree with our tactics. That is fine. Unless you have a kid who risks getting abducted, arrested, or worse because of their actions on the Internet, it probably is hard to understand!