What if you were waving the cigarette around in your hand, and it went in some woman's eye who was sat next to you. She might pick up the ashtray and hit you in the face with it ...... but as her depth perception would be screwed up (seeing as she has a butt in her eye), she might miss and accidentally hit a small disabled child who was working as a shoeshine boy. The shoeshine boy would get knocked over and in the commotion, his tin of polish would get knocked into the air and land on someone's face. Then, what if there was a a 'Care in the Community' person was working there as a barman and, seeing the guy with the black face, he may mistake him for Idi Amin. He could be so frightened that he runs out of the pub, goes home and comes back with a samurai sword, which he would use to murder everyone in the entire pub?

What then?