We discuss the dangers that scalable Internet functionality may present to the real world, focusing on a simple yet impactful attack that we believe may occur quite soon. We offer and critique various solutions to this class of attack and hope to provide a warning to the Internet community of what is currently possible. The attack is, to some degree, a consequence of the availability of private information on the Web, and the increase in the amount of personal information that users must reveal to obtain Web services.

Avi Rubin's latest effort; this paper is profiled in today's NYT.