Parents have no idea what goes on in schools
This sort of thing is only going to become more common. Actually, this general sort of thing—kids being cruel, even extremely so—has been going on for as long as anyone who pays attention can remember. All the people who are shocked by this are just showing that they’ve had their heads in the sand for years. It’s time to realize what’s going on and pull your kids out of school, or avoid putting them in in the first place.