George W. Bush assured Americans this week that his administration was doing nothing illegal by maintaining a record of telephone calls made by about 200m US subscribers. But the president has already made clear that his definition of what is legal applies to virtually anything he chooses to authorise in the name of national ?security.

The leak on Thursday to the USA Today newspaper revealing that the US National Security Agency was keeping a log of billions of calls made each year in America ? in what is surely the largest database ever assembled ? is troubling at many levels. It is the latest example of the administration?s habit of intruding on American freedoms ? whether the right to privacy, habeas corpus or other ironclad constitutional protections ? without having obtained permission from the courts or Congress.