Our friends in the UK seem to be stealing a march on us in the Big Brother race, thanks to RFID technology. RFID, if you haven't heard, is a scheme that basically puts a chip about the size of a piece of dust attached to an antenna into, well, just about anything. It can be read by a scanner at a distance of up to about 20 feet. Today.

Alan Robinson, manager at the Tesco store on Newmarket Street, Cambridge, seems excited about this store's current trials of RFID tags in Gillette Mach3 razorblades. Speaking to Smart Labels Analyst magazine in April this year, he said: "We are cooperating with this trial in every way we can - we would like to be a test bed for many more trials of this kind." He adds: "We haven't had a single customer ask what the tag is doing in their packet of razors!" Notoriously subject to theft (small, expensive and easily resold), these blades were tagged by Gillette, which earlier this year ordered 500m radio-frequency ID tags from the aptly named Alien Technology Corp. At the Tesco Cambridge store, reports the magazine, a camera trained on the Gillette blade shelf, and triggered by the tags, captures a photo of each customer who removes a Mach3 pack. Another photo is taken at the checkout and security staff compare the two images to ensure they always have a pair.

Now that doesn't sound so bad, does it? Less shoplifting = better prices for the rest of us, right? Well, the problem is that anybody with a scanner can read the devices. And the people producing them are pushing to have them included in virtually everything and pitching to retailers how useful it's going to be. Which means that the burglar standing outside the jewelry store is going to be able to tell from a distance whether you bought a cheap stone or splurged on the big diamond. And the government agent standing outside the bookstore can tell at a distance that you've picked up this month's Penthouse, or whether you bought Ann Coulter's new book or Hillary Clinton's. And unless you have a scanner yourself, you have no way of knowing what has the tags in it. The shoes you're wearing, for instance. Very handy for anyone who wanted to track you for whatever purpose.