An elderly lady is walking on the street

She's carrying a bag in each hand. One of the bags has a hole in it and with every step she takes, a $20 bank note falls out. A policeman notices and stops the lady.

'Dear lady, there's money falling out from your bag!'

'Oh, dear Lord! Thank you for telling me, my love. I'll turn around and check whether I can find a few stray bank notes...'

'But where is the money from?' asks the policeman. 'Did you perhaps... steal it?'

'Oh no, silly! There's a stadium in front of my house and the drunk supporters always come to pee on my fence. When they get to the bushes and start peeing, I jump out with a pair of scissors and say: "Pay $20 or I'll cut it off!". So that's how I got the money.'

'Ingenious!' laughs the policeman. 'And so what's in your other bag?'

'Well, not everyone pays...'