The ability to track people is intrinsically risky. First of all, technologies for tracking people can repress individuals and even populations. Unlike a mere ID card, however, the ordinary person with an implanted ID cannot escape surveillance. EFF believes that perfect surveillance, even without deliberate abuse, tends to chill political, artistic, and scientific activity.

Second, even when introduced for seemingly "good" purposes, people-tracking technologies create an infrastructure that can enable later repression. Great Britain, for instance, began issuing wartime ID cards in 1939 in order to administer rations. In 1952, the system was discontinued because police had too much discretion to stop people for ID checks -- and they were using it.

Proponents of ID systems often try to start small, planning to expand the system later. When Australia attempted to introduce a national ID card, one planning document stated: "It will be important to minimize any adverse public reaction to implementation of the system. One possibility would be to use a staged approach... whereby only less sensitive data are held in the system initially with the facility to input additional data at a later stage when public acceptance may be forthcoming more readily."

Third, while people are enthralled by the "gee whiz" element of new technologies, those very technologies often have unintended consequences not foreseen by their designers. The security problems associated with devices implanted into someone's body are particularly severe. Most implanted devices are not intended to communicate with the outside world. The VeriChip is in a new category and is likely to contain unforeseen potential for failure. And because the VeriChip both permits tracking of people and communicates sensitive medical information about them, the costs of failure are especially high.

Although the VeriChip is intended only to communicate with authorized parties, there is no guarantee that it is secure. What safeguards prevent people from being tracked without their consent or followed by parties they did not authorize to track them? It would be tragic if a kidnapper could track a child by an ID chip. Existing "tamper-proof" smart cards can have their data downloaded without any physical contact with the card.

Finally, it is unclear that implanted chips are more useful than bracelets or dog tags for any ID or data functions. As the chips become smaller, meanwhile, the risk of unconsented implantation of ID chips could increase.