This is quite possibly the WORST IDEA in the long sad HISTORY of BAD IDEAS!
Giving immature human beings who are prone to acting up and pitching fits access to metal containers filled with food and expecting THAT to stop a armed intruder from BLOWING PEOPLE'S BRAINS OUT with a AUTOMATIC RIFLE?
Yeah, this is just stupid. Utterly, completely, COLOSSALLY STUPID. The smart thing to do would be to promote (and enforce) better gun registration laws and require a police or security guard presence at the school. Instead this principle has just given every student access to a potential thrown weapon and permitted them to use it (instead of investing in a smart security plan like possibly locking down part of the school while evacuating the rest)!