Ever heard of playing "Yank Man"? Thats when the non-customer has a line sticking out of a window, door, vent, or any other orifice they can find. The tech discovers this blatant act of theft and proceeds to yank on the cable with the force equivalent to an aircraft carriers's catapult. Hopefully you hear the satisfying bang/thump/crash of the deserving idiot's equipment hitting the floor. Of cource I recomend preparing for this action, like parking around the corner engine running and door open. Unhooking the cable first is good too, if you get a reaction just flip them the bird and move on. If there seems to be no notice that there is no picture on his tv... well... happy hunting.