While I can certainly understand the anger and frustration at the thought of such a thing happening, I can't imagine anything short of
more laws requiring, say, a compulsory video camera embedded into the screen, to show just WHO you're talking to.

Not a very good idea.
Evil finds a way with anything...cars, radio, even cans of whipped cream!

It's just life. Best thing to do is EDUCATE the kids, and don't create an atmosphere where they feel they have to "go behind your back" to do whatever
they're gonna do anyway. IMO, of course.