Ballistic armor companies are marketing protective products designed for the military to parents and schools. Some people see the items as unsettling but prudent; others find them infuriating.
My personal conspiracy is that the American government refuses to actually do anything about school shootings because they want you guys to stop sending your kids to public school.
That doesn't make any sense though, why would the government not want people to use the facilities they provide? The "take everyone's guns away" theory makes more sense.