@arstechnica 12-year old. Who has primary responsibility for their safety?
And I say this as a parent with two kids, youngest of which is 17. It's freaking impossible to keep track and/or block kids from access to danger once they have a laptop, desktop or $martphone.
The best you can do is walk them through the dangers you can say and try and keep checked in (absolutely no comment but "Oh, cool" or ") on what they're interested in.
You'd like to blame the platforms. Deeper pockets.