I have a teen daughter as well. My wife and I go back and forth on this, but my take is that she's learning how to communicate with her peers in ways that I will never understand. I don't have to live in the world she will inherit, I'll have my furrowed brow and my 401k and she'll be deciding what being an adult means for her.
At the end of the day, I can only coach her on how to conduct herself online, she's going to be the one out there.
This is the age when our ancestors were teaching there kids about the tigers, lions and wolf's out there. If they tried to keep them safe that would have been the death of the whole tribe, as the kids that didn't understand the dangers would have done something stupid and got a bunch of people killed.
Sheltering kids is bad, teaching them and finding a mutual understanding is the best way to handle them. There are predators out there and they need to be thinking about that whenever they make an interaction on the internet.
At the end of the day, I can only coach her on how to conduct herself online, she's going to be the one out there.