I just sent this letter to my MP.
Dear David Cameron,
Although we have all been shocked and appalled by the acts of terrorism witnessed in London today, I wish to request that you do not allow the Government to use this tragedy as an excuse to push the ID cards legislation through government. I do not believe that ownership of ID cards would have helped to prevent or diminish the effects of today's events in any way.
It is not possible to strip-search and biometrically validate the identity of every one of the millions of people who use London's transport each morning. In fact, sufficiently motivated people would be able to bypass even such an Orwellian nightmare of a security system.
I suggest that if only a fraction of the funds earmarked for a national ID card roll-out were invested in the intelligence forces tasked with detecting, infiltrating and dismantling terrorist organisations it would have a far more greater effect on terrorist activity than the proposed introduction of ID cards. Terrorism is a human factor, and intelligent humans are needed to combat it, not an ill-thought-out technical solution that has already been proven to to be unreliable.