A number of religions in Ankh-Morpork still practiced human sacrifice, except that they didn't really need to practice any more because they had got so good at it.
Terry PratchettI get it,' said the prisoner. 'Good Cop, Bad Cop, eh?' If you like.' said Vimes. 'But we're a bit short staffed here, so if I give you a cigarette would you mind kicking yourself in the teeth?
Terry Pratchett