I've seen it all
People, I swear ... On my HOU-SAN this morning not only did the rube (if you'd seen 'em, you'd agree) immediately across the aisle from me dump the residual water out of his cup of icewater onto the cabin floor, but over the course of a couple of hours used it to drink three roadies from his backpack ... as an added bonus, he tried to get off before the "ding" and pretty much pushed everyone aside getting out of the cabin.