A little old lady is walking down the street, dragging two large plastic garbage bags with her, one in each hand. Unfortunately, there is a rip in one of the bags, and every once in a while a $20 bill falls out onto the pavement.
Noticing this, a policeman stops her. “Ma’am, there are $20 bills falling out of your bag.”
“Oh, really? Damn!” says the little old lady. “I’d better go back and see if I can collect them. Thanks for the warning.”
“Well, now, not so fast,” says the cop. “How did you get all that money? You didn’t steal it, did you?”
“Oh no,” says the little old lady. “You see, my back yard is right next to the parking lot of the football stadium. Each time there is a game, a lot of the fans come and pee through the bushes, right into my flower beds! So, I go and stand behind the bushes with a big hedge clipper, and each time someone sticks his little thingie through the bushes, I say, ‘$20 or off it comes!'”
“Well, that seems only fair,” laughs the cop. “Ok, good luck! By the way, what’s in the other bag?”
“Well,” says the little old lady, “not everybody pays.”