Protagonists of privacy rights should think about this:
If we are identifiable by registration numbers on the cars we drive every day then we could be identifiable by imprinted bar codes or fingerprints anywhere by any agent - store merchant, another fellow passer by. Well that could be made illegal - no - that would be an abridgment of liberty. Fortunately quick identification by barcode, registration plate, fingerprint or DNA trace is still a bit technologically out of reach.
But one day it will be feasible, one day it will be possible to identify a person by facial features as quickly and surely as is done by passport agents at the border. Will you want to hide your face from the world and other people among which there will be masses of robotic paparazzi documenting your whereabouts. I think you will want to appear to the world with your face boldly uncovered. How otherwise would you be free?
So the issue of privacy is not central here because we cannot prevent our private lives to be broken into. The treasure to protect is our safety from unjust prosecution for the lives that we will have to lead in the open. And our lives will be led in the open and not in "undisclosed locations" because our thirst for liberty will demand that. So we guard against the expansion of prosecutorial powers in a world where technology will make us lead completely documented lives. We should be able to say to that - so what?