During the Second World War the government introduced compulsory ID cards as part of their emergency measures. It was not until seven years after the War that ID cards were finally withdrawn. Clarence Willcock was instrumental in this process; his refusal to show his ID card when stopped by the police in North London raised questions about their use in peacetime Britain and contributed to the withdrawal of the cards in 1952. Now the UK government is introducing ID cards again. What factors are the same, what are different and how can we learn from the past to resist their introduction now?