The thought goes like this: most of the time we think of privacy the wrong way. What privacy rests on, paradoxically, is positive I.D. Your thumbprint, or your D.N.A., are technical wonders, because they are Unique Identifiers: they give verifiable evidence of your individual existence. In the computer age, these things can be tied to various database clusters: your credit, your medical and criminal histories, and so on. It is GOOD that we are within sight of a method of establishing the unique identities of every soul on earth.
What is at issue is this: who has access to the linked database, which parts, and under what circumstances. If you want to buy on credit, you need to give the credit-issuers access to your credit history. If you want good medical treatment if you arrive at Emergency in a coma, the doctor needs to access your medical history, for which he has to make a postive I.D. And so on.
So what is at issue is NOT the creation of "National I.D. Cards," or anything of the sort. They already exist, anyway, and if we would acknowledge that, we would be able to clean them up and make them less ad-hoc. What is at issue is this: who has access to your records, in what way, for what purposes, and what are the fines and criminal sanctions that are spelled out for "illegal trespass." Without Positive I.D., though, there can be no real definition of this trespass.
Am I being clear?