Can't we just hand teachers a stick and let them spank the deviousness out of these kids? That's all we need, teachers given rights to raise those mad teens and kids we are getting nowadays. Since parents aren't doing anything to control their lousy children, then the school should. I wish hitting was allowed just like back in the days...I can see the difference at least between me and my parents as they were young. I can see how this tough ability of teachers shaped them as respectful beings.
So I really don't think security guards are necessary, just let the old teachers be back.