The UK supermarket chain Tesco has admitted testing controversial technology that tracks customers buying certain products through its stores. Anyone picking up Gillette Mach3 razor blades at its store in Cambridge, in the east of England will have his or her picture taken.
The London-based Guardian newspaper, alerted by Katherine Albrecht, director of US-based Consumers Against Supermarket Privacy and Invasion and Numbering, to the use of the smart electronic tags, has found that tags in the razor blades trigger a CCTV camera when a packet is removed from the shelf.
A second camera takes a picture at the checkout and security staff then compare the two images, raising the possibility that they could be used to prevent theft.
"Customers know that there are CCTV cameras in the store," said a spokesman for Tesco. He went on to insist that the aim of the trial was to provide stock information and not security, but the manager of the Cambridge store, Alan Robinson, has already described how he presented photos of a thief to police.
The trial uses radio frequency identification (RFID) in which tiny chips can communicate with detectors up to 20ft away. The chip can then return information -- anything from a unique serial number to more complex product details. Or, as in Tesco's case, it could trigger a camera.
Retailers have hailed the technology as the "holy grail" of supply chain management but civil liberties groups argue that the so-called "spy chips" are an invasion of consumers' privacy and could be used as a covert surveillance device.
The technology is mostly used to track batches of products through the supply chain.
But manufacturers want to go a step further and tag each individual product: everything from yoghurt pots to clothes.
One potential problem with RFID tags is that they can still work long after the product has been bought.
If the tags become as ubiquitous as the manufacturers would like, people could be bristling with the chips in clothes and possessions. Anyone from police to potential thieves could work out exactly what they carry.
Manufacturers, however, insist that the chips can be disabled at the point of sale.
"You can disable the tag by erasing the data on it and this can be done at the checkout," said Jon Parsell of UK-based RFID Components, which supplies RFID systems to retailers.
Transport for London (TfL) is also using RFID-style chips in its new Oyster smart cards to allow users to travel around the tube network. The intention is that registered users will have information such as their names and addresses stored on the cards, which would eventually replace season tickets.
A spokesperson for TfL said that the entry and exit points of each journey made by Oyster users were recorded and that, technically, it would be possible to track people through the tube network.
Nicole Carroll, marketing director for TranSys, the consortium responsible for implementing the system, told reporters that all the journeys made by a user would remain stored in a central computer for the lifetime of the card.
Barry Hugill of the civil liberties lobby group Liberty expressed concern about "function creep" -- information recorded for one purpose and used for another.
"We want quite clear legal guidelines as to what information companies, government agencies, local authorities are allowed to glean [and] what they can do with it," he said.