In the US it has helped put some of the biggest godfathers of organised crime behind bars. It is seen as a crucial weapon for fighting crime throughout the European Union, in Australia and Japan - virtually everywhere, in fact, except Britain and Ireland.

In Britain we prefer to subject terror suspects to executive house arrest - as the home secretary is proposing - and to risk seeing drug barons go free, rather than allow information obtained from telephone tapping to be used as evidence in court.