We have become digital citizens and playing into this space is inevitable, says the writer. File photo

London - Have you ever had the feeling your computer is watching you? That somehow it knows what you were looking at yesterday, or last year? And that rather than being your technological “friend” it behaves more like a slick second-hand car salesman?

You fancied flying to Paris so you checked out airfares... and before you knew it, your Facebook page was plastered with advertisements for hotels on La Rive Gauche. Your daughter bought a record by One Direction. Now, the family computer is bombarded with ads for boy band concerts.Anne Crabtree, a 32-year-old writer, knows exactly how this feels — because it almost ruined her wedding day.

“I had used the computer to help me find my dress, shoes and jewellery, but obviously I wanted to keep them secret,” she says. “But adverts featuring them kept popping on to the screen when my fiancé was in the room.

“Time and time again I would have to slam my computer shut to stop him seeing the dress I was wearing on the big day. By the time we actually got married, I was a nervous wreck.”

At least Anne managed to carry her secret with her until the ceremony; others haven’t been so lucky. A case emerged recently of a man who bought an engagement ring on the internet, only to have his surprise ruined when his girlfriend received computer ads for rings when she logged on.

Then there was the case of a secretly gay man who had been browsing for information about his local gay scene. His computer later “outed” him when a colleague using it was sent ads aimed at gay men.

So why does this happen — and, more importantly, how can we stop it?

It is all because of something on your computer called a “cookie”. The origins of their name are unclear, but cookies are vital to the running of the internet. When you visit a website, that site places a unique cookie on your computer so it recognises you when you come back. It allows the website to remember your login details and other pieces of information to save you entering them again and again.

If, say, the site offered up weather information, it might remember that you were interested in conditions over a particular town, and so on.

These devices — known as “first party cookies” because they involve an exchange of information only between you and the site — make shopping on the internet possible. If you shop for groceries over the internet, for example, cookies allow you to update your shopping trolley day after day, returning as you remember to add new products before moving to the virtual checkout at the end of the week.

And cookies can remember your credit card details to save you having to enter them over and over again. So far, so good.

Problems arise when advertisers get involved. You may think all the websites you visit as you use the net are free, but they aren’t. In return for using them you automatically part with slices of information about yourself that can be used to send advertisements to the pages you look at as you surf.

This is why Anne was bombarded with all those wedding dress advertisements after spending time looking for her wedding outfit on the internet. This happens because of “third party” or “tracking” cookies. These are placed on your computer by companies who profit from finding out what interests you or what — from your searches — you are looking to buy.

These companies — they could be household names like Google or others you have probably never heard of, such as Math Tag or Criteo — use this information to send targeted “behavioural” advertisements to you. They rely on vast networks of retailers who allow them to send their cookies to you each time you visit their websites.

These information-gatherers argue that the data they collect about you is anonymous and they don’t actually care who you are — only that they are sending you adverts they think you need.

A recent investigation found that innocent visits to the websites of companies such as Tesco or Debenhams resulted in dozens of third party tracking cookies being placed on the hard drives of computers. During one 15-minute surfing period, one investigator’s computer was inundated with 600 cookies, 350 of which were the tracking variety.

Theoretically, you can stop these by adjusting some settings on your browser — the programme that allows you to surf the net, such as Internet Explorer.

However, some users find these settings don’t always work or are sometimes sidestepped by unscrupulous trackers. Last month, a class action lawsuit was launched against Google in the UK when it was discovered it had secretly placed tracking cookies on to Apple computer and iPhone users who were browsing with Safari — an Apple browser that boasted of automatically blocking third party cookies.

The lawsuit alleges Google deliberately found a way around this protection while telling users all its tracking cookies would be blocked by Safari.

“So on the one hand Google told users their surfing habits would not be tracked because of the Safari protection, and on the other hand they had people at Google actually writing programming code that would undermine Safari’s cookie protection,” says Dan Tench, the partner at Olswang solicitors leading the class action.

“That is an invasion of privacy and a breach of European and UK data protection legislation. Google has already been fined $22-million by the Federal Trade Commission for doing this in the US.”

Google declined to comment on the case. So far, just over 100 people have joined the British class action (among them, the man whose wedding proposal was revealed and the gay man “outed” by his computer).

Under EU legislation introduced last year, the home pages of websites are supposed to flag up the fact that third party cookies may be placed on your computer if you view further. The problem with this is you generally have to agree to accept cookies if you want to use the site. And many people have no idea what cookies are anyway.

In the UK, spending on internet advertising is expected to top £5-billion this year. The problem for the industry is that if everyone blocked tracking cookies, manufacturers would stop spending on ads because they could not be directed at the people they are targeting. In turn, websites wouldn’t make money from advertising and all that “free” stuff would suddenly disappear.

Some argue the internet itself would die from a lack of advertising income.

“If you accept that advertising funds the internet — and we find that consumers do understand that — then you have to realise you are going to get ads as you browse the web,” says Nick Stringer, director of regulatory affairs at the Internet Advertising Bureau (IAB), which represents 800 companies working in digital marketing.

“Our argument is that you might as well get advertisements for products and services that you are actually interested in.”

It might not be an argument that cuts much ice with Anne, who says she had a wedding day to remember, no thanks to those pesky cookies. -Daily Mail

* For information on how to manage cookies, visit youronlinechoices.eu/uk