Tony Blair has said that Identity Cards had an "important roleâ€ to play in fighting serious crime.... How, exactly is that, Tony? Do you really expect people to say 'Excuse me, Mr. Armed Criminal, before you point that gun at me, can I have a quick look at your ID card?' More than this, do we really expect the ID card to say 'Occupation: Armed Criminal'?
The only way this can work is if the cards become incredibly intrusive, an internal passport, to try and catch the known felons (ignoring the problem of the ones we don't yet know about).
Didn't the USSR have internal passports?
(Edit: Bruce Schneier has just posted on this issue, as well as others. He says ID checks don't make sense. Everyone has an ID. Even the 9/11 terrorists had IDs. What we want is to somehow check intention; is the person going to do something bad? But we can't do that, so we check IDs instead. It's a complete waste of time and money, and does absolutely nothing to make us safer.