CDT has been looking into the impact of digital authentication on privacy. While most of our focus has been on embedded serial numbers and digital signatures, we have become increasingly concerned with several standards - IPv6 and cable modems in particular. These standards would likely take control of information away from the user by creating the equivalent of Internet ID cards. Unlike the serial number in Intel's Pentium III, IPv6's gradual standard setting process and implementation have made it difficult for advocates to focus limited resources already overtaxed by other threats to privacy online.

We view Mr. Frezza's timely column as an important warning signal. It is time to put a greater focus on the privacy concerns in IPv6, before it is too late.