Body armor can protect against small arms.
But not against heavy artillery. The massive scale of the barrage being leveled at kids today by the entertainment industrial complex is far more than most parents can defend against. It's kind of like throwing someone into the stormy North Sea, and giving them a personal floatation device to keep them safe. Ii might work for a few minutes, but they're still going under. The sewer is backed up and our society is drowning in filth.