Weekend 'Nazis': The most popular units at the War & Peace Show in Kent are Nazi SS divisions. John Sweeney asks whether these re-enactment groups are just harmless living history societies, or whether the UK's tolerant laws have inadvertently turned them into a magnet for extremists from here and abroad. He finds the controversial Holocaust denier, David Irving, at the show; discovers a disturbing trade in Nazi and holocaust paraphernalia, banned in many European countries; and in the beer tent, secret cameras record the conversations of white supremacists, racists and admirers of Hitler.