I never had any objection to the principle of carrying an official ID card. Like most people I have enough information packed in my wallet to enable anyone to find out almost anything they wish to know about me. I'm sure that plenty of people already know far more about me than I do & I'm quite sure that not all of them are entitled to that knowledge.
What I do object to is the idea of me & all law-abiding people being forced to carry one of these things when criminals & illegal immigrants* will obviously find ways round this. As these are the very people most likely to pose a terrorist threat I don't see how going to this vast expense could do the slightest good. Also, when was the last time you heard of a government-funded computer programme costing way over budget actually working?** As usual they're fooling themselves or being fooled by the people most likely to profit from it.
*PS. Depending on whose figures you believe there are 500,000 illegal immigrants in this country. There are another 250,000 failed asylum seekers who should have been sent back to where they came from but have simply disappeared. The government denies these statistics but refuses to publish its own. The truth is that nobody knows how many there are or where they might be. I'm not trying to say that they are all terrorists but it's quite possible that some are. If these people can live here illegally & claim benefit without any problems, how on earth is anyone going to force them to carry a genuine ID card? They will obviously use stolen or forged documents which makes the whole idea completely ridiculous. I sometimes wonder if the geniuses who dream up these schemes live on the same planet as the rest of us.

**PPS. This makes sobering reading. The problem is that they never learn.
http://www.smithsrisca.demon.co.uk/HE1itdis.html