If someone comes up with an App that lets kids remotely control a robot arm that picks up rocks and launches them or throws punches at defenseless passersby, we may be in some danger.
But rocks are heavy. And punching sounds a lot like exercise to me.
From what I’ve seen, that sounds like more effort than many of them would be willing to engage in. Plus, it would be hard to hit your target while simultaneously texting your friends that you are tormenting innocent strangers.
And some innocent strangers punch back.