Let's use phone taps and abandon 42 days' detention

Jacqui Smith, the Home Secretary, has announced that she wants to hold terror suspects without trial for 42 days, up from the current 28 days' internment.

Last night on BBC TV's Question Time, an audience member asked why phone tap evidence could not be used in court.

Baroness Ashton, leader of the House of Lords, repeated the excuse that if it was used then the security services would have to reveal how it is carried out.

Why?

When someone appears in court for speeding or jumping a red light, the police don't explain how a Gatso works.

If there is tape of Muhammed telling Abdul he wants to blow up a nightclub to "kill the slags", what does it matter how it was obtained?