Since September 11, security has become such a crucial concern here in France that authorities sometimes end up looking slightly silly just to avoid feeling sorry. One night last November, for example, a heavily armed police strike force arrested four hooded men wearing combat outfits and carrying rucksacks, as they were creeping up to the house of the French minister of justice, Marylise Lebranchu. The quartet turned out to be a commando belonging to the Liberation Front for Garden Gnomes, a collection of harmless oddballs whose self-appointed mission is to kidnap "captive" garde