Chuggers are bad for charity in the long run

I have a face that I reserve for clipboard-wielding strangers on the street who bound towards me like puppies. By staring expressionlessly into the middle distance and shaking my head, maintaining my stride, I hope to convey the message that I know they have a job to do but, should they attempt to talk to me, a plague of locusts will rain down on their heads and their houses will be reduced to a heap of ashes. It usually does the trick.