Ihre Papiere, bitte!

ID cards back in the news again.  I've had my say - see posts of 23/1/06 and 8/7/09 - and I have little to add.  I think it is inevitable that they will be introduced sooner or later, but I'm unsure that they will prove to be the "silver bullet" that proponents promise.  I don't want them to end up as simply another excuse for the authorities to be able to pull you over and demand you prove who you are.