AN OBVIOUS truth can be difficult to face. On Monday February 18th Mohamed al Fayed told a British inquest into the death of Diana, princess of Wales, and his son Dodi, that the pair were murdered in a conspiracy that included the British royal family, secret service and government. (In passing he called the Duke of Edinburgh a “Nazi” whose name “ends with 'Frankenstein'.”) In fact the court proceedings are showing that the pair were the victims of their drunken chauffeur. Yet public hunger for far-fetched theories of all sorts is insatiable. The most frequent internet postings concern an alleged American-government role in the terrorist attacks of 2001. America features strongly with cover-ups of alien life, Elvis's faked death and the Apollo moon missions.