Ah but if you give a preschooler a shiny vest and a sling shot to launch the rocks and tell everyone they will be shot if they don't listen to the kids with slingshots then most of them behave but a few break the rules and throw their rocks anyway. Eventually the kids with slingshots will realize they can shoot the other kids anyway, then they make the other kids give up their rocks and the only ones left with rocks are the kids with slingshots and the kids that break the rules and pick up rocks off the ground to throw.