ID cards themselves are no big deal. It is the database behind the UK card that sends shivers down everyone’s spine, because it will record when and where the card is used. Usage records cannot be deleted and are open to inspection by snoopers from the police, spies, HMRC etc. The cardholder must keep their records updated for the rest of their life, with draconian penalties if they don’t.
Finally the (enormously expensive) system that is being developed for the UK ID card is unlikely to work as the Home Office think (it will not be totally reliable). It offers few of the benefits of a properly thought out system. Such benefits would include the ability to verify your ID online, which the UK system cannot do. The UK ID card has shiny contacts on it to make it look like a “chip and pin” card. They are for show. The ID card chip uses (inherently unsafe) RFID technology.