He drew attention to a demonstration by researchers at the University of Washington of a surveillance system that automatically tracks people through the, which consists of a .
"Basically, the kit contains a transmitter that you stick in your sneakers and a receiver you attach to your iPod. This allows you to track things like time, distance, pace and calories burned. Pretty clever," Schneier wrote on a blog post titled "Tracking People by their Sneakers," published Tuesday. "However, it turns out that the transmitter in your sneaker can be read up to 60 feet away."
Because the radio frequency identification, or click for PDF). The team said they built a surveillance device, which cost about $250, and integrated the surveillance system with Google Maps., transmitter broadcasts a unique identifier, people can be tracked by it, the University of Washington researchers said in their paper on Nike+iPod Sport Kit (
"Details are in the paper," Schneier wrote. "Very scary."
A Nike representative said the sports apparel company had no immediate comment. Apple Computer, which makes the iPod, said it had no comment on the matter.
The chips have no personal identifying information, yet can still be used to track people, Schneier said. He argues that as long as the RFID chip has a unique identifier, it can be used for surveillance. It can be scanned and linked to a user's physical identity, he said.
"To me, the real significance of this work is how easy it was," Schneier said. "Unless we enact some sort of broad law requiring companies to add security into these sorts of systems, companies will continue to produce devices that erode our privacy through new technologies. Not on purpose, not because they're evil--just because it's easier to ignore the externality than to worry about it."
RFID tags are increasingly popular in the retail sector, where companies such asuse them to track shipments and keep a close check on stock levels. But campaigners have warned that the if they don't destroy these tags after they buy the item.
Tom Espiner of ZDNet UK reported from London.