and it's gun free zone friendly! SME Chuck Haggard at PF pointed out in this fascinating thread that one of the most important thing you can have to thwart an active shooter is......a doorstop (the one he recommends is linked). This nugget of wisdom REEKS of common sense and is one of the reasons I love that forum.
Other forums have Walter Mitty-esque moments of fantasizing of say someone running and out grabbing his "terrorist interdiction bag" but this, this is a bit more realistic. Of course, good on ya if you are ready to take on an active shooter. Preparation never hurts.