Days after 9/11/01, New Jersey surgeon Richard Seelig didn’t want to take any chances that his body could be lost in a disaster. After seeing the firefighters writing their social security numbers on their forearms, he knew there must be a better means of I.D. Dr. Seelig became the first human to be injected with a Verichip: a tiny radio frequency identification chip the size of a grain of rice. Is this the dawn of the human bar code?

Applied Digital Solutions, the Florida-based company behind the Verichip, is now working with the Food and Drug Administration to bring human bar codes to the general population. Already, Verichips are being used abroad. Government officials in Mexico have been injected with Verichips to help locate them in the case of a kidnapping. In Barcelona, a beach club is injecting patrons with the chips in lieu of hand stamps.

When combined with global positioning systems, the Verichips could save lives–for example, helping kidnapping victims to be tracked down. Of course, they could also violate privacy. Trucking companies and hospitals are already using variations of radio frequency IDs on badges to track employees. But what happens when the IDs are under the skin and can’t be readily removed?