A little old lady is walking down the street, dragging two plastic bin
  bags with her, one in each hand. There's a hole in one of the bags and
  every once in a while a £20 note is flying out of it onto the pavement.

  Noticing this, a policeman stops her...."Ma'am, there are £20 notes
  falling out of that bag..." "Damn!" says the little old lady....."I'd
  better go back and see if I can still find some.  Thanks for the warning!"


  "Well, now, not so fast," says the cop.  "How did you get all that money?"
  " Did you steal it?"

  "Oh, no", says the little old lady.  "You see, my back yard backs up to
  the parking lot of the football stadium. Each time there's a game, a lot of
  fans come and pee in 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!"

  "Hey, not a bad idea!" laughs the cop.  "OK, good luck!  By the way,
  what's in the other bag?"

  "Well", says the little old lady, "not all of them pay up"!

:-D