O'Carroll was working as a press officer for the Open University in the 1970s when he was told of the existence of the Paedophile Information Exchange (PIE) after admitting he was a paedophile to lesbian members of the OU Women's Group. At that time, he was editor of the OU staff newspaper "Open House" and had been covering a Women's Group meeting on homosexuality. In his book "Paedophilia: The Radical Case", he writes: "The general public in the UK has long been aware of 'child-molesting' and 'perversion'. But only in the 1970s did it come to hear about 'paedophilia', a designation suddenly lifted from the obscurity of medical textbooks to become a crusading badge of identity for those whom the term had been designed to oppress".