I think about that a lot when my professors are boring the shit out of me. Freshmen year we had mandatory Alice training. We were told we could use whatever we had to to save lives. So I would totally stack a bunch of shit against the doors, then get computers and tvs (expensive shit) to throw at or bludgeon the attackers with. Just so I could spend as much cleanup money as possible haha. Also, I would totally take some lights out of the ceilings, break them, and use the sharp, jagged lightbulb tubes to kill the attackers as well. I get really bored in class. Especially non major, liberal arts classes that seem pointless to me.