They know where you live

What price privacy, when a click of a mouse will give anyone who's interested your name, address and spending habits?

If I know your name and you vote, I can find out where you live in less than 30 seconds - and so can anyone else with a computer. It is perfectly legal, and all part of the technology revolution. Directory websites such as 192.com not only provide on-line UK telephone directories, but have the entire electoral register with over 25 million adults on their database. Tap in a name and up pops the address.

If I know your name and you vote, I can find out where you live in less than 30 seconds - and so can anyone else with a computer. It is perfectly legal, and all part of the technology revolution. Directory websites such as 192.com not only provide on-line UK telephone directories, but have the entire electoral register with over 25 million adults on their database. Tap in a name and up pops the address.

It may be legal, but many argue that the law has not yet caught up with the internet revolution and put in place proper safeguards. In this brave new world there is no real privacy. The legislators are struggling with the terrifying power of computers to, as the marketing companies so innocently put it, "datamatch" information from a wide range of sources to build a detailed picture of you and your spending habits. If you don't mind the world knowing all about you, that's fine. But if you prefer anonymity, hard luck.

Long before the internet, electoral registers could be used to find individuals, but the hard-copy registers were only held locally, making it an difficult task. I used to know a man who traced debtors for HP and gas companies. Once a month he would disappear into the bowels of the GLC's County Hall to look up London's electoral registers, which were filed ward by ward. He would reappear days later with only partial success to show for his pains. To look at other parts of the country, he would have to go to town halls or local libraries. It was a labour-intensive task, and only for the determined. But not any more.

The issue of this public register being used commercially has caused considerable controversy. Many people feel aggrieved by it; they filled in their electoral register form in order to vote, not to be pursued by telemarketers or any no-good with a computer. All adults are legally required to fill in the electoral register form, so there has been no legal way to opt out.

Who uses this information? Have you had those annoying calls from someone trying to sell you insurance, double glazing or cheap gas? That's the telemarketers. How did they target you? Off the electoral register. The register is available because elections officers can sell the register at £2.50 per 1,000 names. Specialist companies then compile it and sell it on as complete databases. Other public registers that are available include the Register of Interest in Shares and County Court Judgements. And the growth of new technology means that personal information can be used in new ways, for example to identify people who have recently moved house, to sell them specific products.

But it is not just salesmen who can find out your details. Criminal cases have been reported in which the electoral register has been used to target victims - as happened in the case of the "Mayfair rapist" and a murder in the Wirral. Using computer databases, well-organised criminals can target the vulnerable or rich.

Is it unreasonable to want to keep your address private? Not according to Simon Davies of Privacy International. "The default position in English law is that you can expect no right to privacy. The new Human Rights Act, which becomes law in October, will change matters, but only slightly. The presumption in England is that surveillance is legitimised."

Simon Davies has warned of the "death of privacy" - and that there will soon be "technology that intimately knows each one of us". But he reserves his biggest condemnation for companies that sell "reverse directory" CD-roms that, if a target's telephone number is tapped in, give an address. These disks combine the telephone directory with the electoral register. "This is very dangerous. It is technically illegal, but these companies base themselves offshore and export discs into Britain."

Privacy International also campaigns against financial institutions that sell your details for marketing. "Not many people realise that when you ask the Post Office to redirect your mail they sell that information on to marketing companies," Davies points out. "The presumption is you have opted in to having your details distributed. You have to make a point to opt out." Privacy International wants to see this situation reversed. "The presumption should be that people want to opt out - keep their details confidential - unless they tick a box saying they do not mind."

Having your name on the electoral roll does have some advantages. When you want to buy something on HP, credit reference agencies use the electoral register to check that you live where you say you do and that you have been there long enough to be a reasonable risk.

And it is not all bad news. Over the last two years the Data Protection Commissioner and the Home Office have instigated research into the availability and use of personal information from electoral registers. Under the new Representation of the People Act, when the next set of forms for the electoral register are sent to every household in the country, there will be an opt-out box to show whether you mind the information being sold on.

"There will be two versions of the register. One with all voters, which will be available to the authorities for elections and matters like the detection of crime," says David Smith of the Data Protection Agency. "The second will contain only those people who have agreed to opt in, and that is the one that can go on sale."

This has sent the marketing industry into something of a panic. John Dobson, managing director of Eurodirect, a firm that sells electoral-register databases, has warned clients to act now if they want to continue to be able to target potential customers. "The inevitable changes surrounding the Electoral Roll 'opt out'," he writes on the firm's website, "mean that companies could lose up to 35 per cent of their potential prospects. Prudent operators are making alternative plans."

In other words, they are already switching to the other databases to collect your personal details.

But Simon Davies says that there is hope. "I believe that there are legislative solutions to suit the 21st century, and that we should strive to agree on these solutions. All of us - privacy advocates and media professionals - are working to create a fairer society, governed in the more transparent and accountable way."