This isnt really a joke, as I have been told it as a true story. A man got a speeding ticket and a photo of himself driving the car. He sent the police a photo of the money (the fine amount). The police sent him back a photo of a pair of handcuffs. He paid up.
I dont really remember the story properly but the police once sent out invitations to criminals to come to a certain address to collect a prize or something. They managed to get most of the people they wanted without the bother of going to find them!!!
The police in one American town were in the habit of sending birthday cards to known Yobs who had played the Underage card.
" Happy sixteenth Birthday A$$h0Ie "