A Chip On Your Shoulder--Or Under Your Skin

Radio-frequency identification (RFID) devices are small tags embedded with microchips that wirelessly transmit data to a remote scanning device. In the past, RFID tags were used for such tasks as tracking inventory in warehouses and preventing shoplifting in clothing department stores. But now a new use is emerging: tracking people.

In other words, the shirt on your back could be outfitted with an RFID tag so small that it's undetectable. Such a tag could track when you enter, say, a shopping mall, how long you spend in each store, and what you purchase.

The European Union is reportedly implanting RFID chips into high-denomination bank notes. And several corporations, such as the Michelin tire company, have begun implanting small RFIDs into their products.

A few technology companies are embracing the controversial devices, including IBM, which recently launched an RFID service. And in a chilling application, Applied Digital Solutions, a Palm Beach, Fla., technology vendor, has developed subdermal RFID tags, called VeriChips, that are about the size of a grain of rice and are inserted under a person's skin. The company says it received orders for nearly 3,000 VeriChips in the third quarter.

I say watch your back.