One of the constant tensions between privacy and technology is that the technology advances so rapidly that privacy policy simply can't keep up. The old ideas of Fair Information Practices, especially the use and purpose limitations that form the bedrock of most privacy approaches, simply can't withstand the assault of technological change. Two recent articles, a blog post by Jeff Jonas (of IBM) and a column by Ari Juels (of RSA) illustrate the depths of the problem.
Jonas sees a world in which location based systems will be able to perform analytic functions to assess your physical movements. Juels sees analytic short cuts to unique identifiers that will fully identify an individual. Both recognize that with the prospect of these powerful technologies ahead of us, old-fashioned concerns with things like the privacy protection in RFID chips miss the forest for the trees. As Juels puts it (and Jonas would surely agree): "Many people have GPS receivers in their phones and are signing up for location-based services, voluntarily (if selectively) disclosing their movements. There's little point in hiding the serial numbers of chips when your mobile phone squeals on you."
I'm not sure how to build a new set of privacy protections in the face of these massive technological changes. But I am increasingly concerned that legal privacy constructs that are now more than 25 years old cannot keep up.