Many restaurants had steel silverware sitting in the open. Anyone walking by could just grab-n-go. Many of the little kiosks had tools sitting around (I've seen screwdrivers, for instance); behind the counter, but a little distraction, and it's yours. Hairspray? Use it with a lighter, and you have a nice flamethrower.
You can get much bigger quantities of such stuff inside the airport (past security). I'd love to document this, but I'm afraid of ending up on some list.
Yeah, and it doesn't really matter. Nobody's going to stop you from buying multiples of the smaller quantity hairspray, in different stores or with friends, etc.
And then, there's this: http://terminalcornucopia.com/