Security expert Bruce Schneier has highlighted privacy concerns around Nike+iPod Sport Kit, a technology which allows the user to track time, distance, pace, and calories burned while performing sport.
In a blog post entitled "Tracking People by their Sneakers", published on Tuesday, Schneier drew attention to research conducted at the University of Washington that demonstrated a surveillance system that automatically tracks people through the Nike+iPod Sport Kit.
"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," said Schneier. "However, it turns out that the transmitter in your sneaker can be read up to 60 feet away."
Because the RFID transmitter broadcasts a unique ID, people can be tracked by it, according to the researchers who built a surveillance device — which cost about $250 (£120) — and integrated the surveillance system with Google Maps.
"Details are in the paper," said Schneier. "Very scary."
Schneier said that this was "a great demonstration for anyone who is sceptical that RFID chips can be used to track people".
The chips have no personal identifying information, yet can still be used to track people, said Schneier, who argued that as long as the chips have unique IDs, those IDs can be used for surveillance. The unique identifier can be scanned and linked to a user's physical identity.
"To me, the real significance of this work is how easy it was," said Schneier.
"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," Schneier added.
RFID tags are increasingly popular in the retail sector, where companies use them to track shipments and keep a close check on stock levels. But campaigners such as CASPIAN have warned in the past that the privacy of consumers could be compromised if they don't destroy these tags after buying items in the shops.