RFID tags - a gross invasion of privacy?

Next time you visit Marks & Spencer, have a close look at the labels on the men's suits and trousers or, if you're a lady, on the bras. You'll see a standard price label, marked with the legend: `Intelligent Label for Stock Control Use.'

The label contains a passive RFID chip and antenna that can be read by a handheld scanner at a range of up to 70 centimetres. The scanner can

identify what the product is, its size and stock control number.

In the US, where the intelligent tag is a lot more widespread, some shopping malls are busy installing scanners at their entrances, ostensibly to check on shop-lifters and other thieves.

It's only a short step before these scanners are installed at shopping mall car parks, and interfaced with licence plate readers. That way the scanning system not only knows what product you've bought, but where you live.

These tags represent a serious potential invasion of privacy. Which is why I ripped the tag off the pair of trousers I bought at the M&S London Marble Arch store the other day, after I left the check-out and before I left the store.

And attracted the attention of a security guard who asked me what I was doing. I explained and he said that a lot of people are unaware of what capabilities the RFID chips have.

Okay - I know M&S wants to improve its stock control, but these tags have massive privacy issues attached to them. At least M&S is reasonably upfront about their usage.

How many other stores are using the tags, but not telling us. Not that they have to - there's no legislation to cover this area...