Keep in mind that invading their privacy means breaking their trust at an age where a large part of their emotional and social development all but requires it. It's a good way to ensure that they won't come to you with any delicate topics later on, like questions and concerns about drugs, sex, or shady behaviour of peers — you know, the part where you want to be that trustworthy parent that they can talk to, always. To them this is like requiring them to use the bathroom with the door open with you looking in — you don't do that after a certain age unless you have a severely mentally handicapped child.
Also, you won't really block them from anything unless you forbid them to meet up with friends with their own unmonitored devices.
> Keep in mind that invading their privacy means breaking their trust at an age where a large part of their emotional and social development all but requires it.
That's why I was careful to say that the default would be to trust them, but only after they show they can't handle it will they be monitored, but in a way they are fully aware of and we would review the logs together. But my point was I hope I never have to get that far -- that I can just teach them to be safe and leave it at that.
Also, you won't really block them from anything unless you forbid them to meet up with friends with their own unmonitored devices.