The Risks digest has an entertaining little story about the hidden dangers of remote central locking, as inadvertently discovered by the female driver of one Mercedes-Benz, parking next to another Mercedes-Benz. It seems there aren't quite as many electronic key-code-combinations as there are cars:

The doors of her Mercedes closed. The already parked Mercedes responded with a happy 'click' and opened it's doors ... She tried several times. When her car opened the other one closed. And vice versa.