That stuff the army experimented with a while back, perfect for schools. Not as good as a gun, I know. But a lot of the teachers are all about butterflys and puppie dogs, not the kind of person to carry a gun. That elementary school principal at Sandy Hook tried to tackle the shooter. If she had hosed him down with the foam that may have been the end of his spree. I read the foam is so strong you can stick a person to a wall and they can't get out of it. That stuff would get all over the shooter, his gun, his mags, his face and hands. And since it is not dangerous there shouldn't be any objections from the non-violence crowd. Not as good a solution as a gun, but a lot better than begging.