Beware the cookie monster: a new law aims to protect privacy
Just how much personal information are websites squirrelling away about us on our own computer?
Are some rogue web sites gathering more than is good for us?
Almost every time you visit a website to browse or even buy something, some details about your visit are stored. It is relatively harmless and makes using the web much simpler.
The storage is in the form of "cookies".
These are simply coded messages left on a computer when you leave a website.
You can find these messages and try to read them, but they usually appear to be gibberish. They only mean something to the website that left them. But is that always fair and could it be a breach of your privacy?
The Information Commissioner's Office thinks it is becoming an increasing problem and has brought in a new law to make sure everyone knows what is going on.
From May 2011, every website must post a warning if they want to put cookies on a computer. The website must get your agreement. If not, the fine is up to £500,000 .
However, to allow website owners to cope with the complexities of the change, the commission will not start to police the new law until early next year.
Some cookies are a benefit when we surf the web. They remember our favourites setting when we visit a site and what we like to see first. Others only stay on the computer while we are on the site and then are deleted when we finish. But some can stay on our computer for years.
Could some cookies threaten our privacy? Should we be worried?
Dr Rosi Armstrong, from the Institute of Electronics, Communications and Information Technology in Belfast, said that many cookies are very functional and useful but some can also build up a profile on people over time.
Most websites behave in a responsible way with cookies. Their credibility and reputation is at stake. But the change in the law could still pose problems for them.
Imagine trying to buy several items from a major internet retailer. Every time you make a purchase without a cookie, you probably have to start again from the very beginning.
The rogues can be in some of the small banner adverts that appear on some website. They are from a different company to the one you initially clicked on and are known as third-party sites. You are tempted to click on them in turn. When you do, some of them then start collecting as much information as they can.
"The aim of the new legislation is for the protection of an individual's privacy," said Ken Macdonald of the Information Commissioner's Office in Northern Ireland.
"There are cookies that obtain an awful lot of information about sites that you have visited, how long you visited, which pages you have gone into and we don't believe that it is always necessary for an organisation to have that information."
He said sometimes cookies are too invasive. "The amount of information going from the user to the website is excessive."
Soon, the opening page on a website will invite you to accept or reject their cookies. If you reject the cookie, then using the site could be very difficult and even impossible. Only click on sites you deem to be safe.
Protecting personal security is not an easy task in a digital world. Ultimately, it is your decision.