On 26 May 2012 the UK's Information Commissioner will implement a 'cookie law' which aims to protect internet users' privacy. The new law, borne out of an EU Directive, requires websites to obtain users' informed consent before setting cookies on their computers.
In light of this new law, we thought it might be useful to explain a bit about cookies; what they are, what they do, the different types, which ones are good and which are potentially bad.
What is a cookie?
Cookies are small text files which are placed on your computer when you visit a website. Their purpose is to recognize you and they can be used for various reasons; from keeping you logged in, to tracking your browsing habits across the web.
Their name is derived from 'magic cookies' - tokens used by UNIX programmers to interact with users/programmes.
There are two types of cookies, session and persistent and they can be delivered in two ways - from a first-party or third party website.
Session cookies remain resident in your computer's memory for as long as the browser is open and don't tend to collect identifiable user information. An example might be a shopping basket cookie which holds the items you've chosen, but will only remember those items for as long as you have your browser open.
Persistent, or permanent cookies, are stored on your computer's hard drive until they expire or you physically delete them. They are used to collect identifying information about you, such as your preferences for a specific website or your general web browsing habits. An example might be a shopping basket cookie which remembers your chosen items the next time you visit the site, even if you've turned your computer off in between visits.
A first party cookie is one which is issued by the website you are visiting. A third party cookie is issued by a different website than the one you are visiting, typically through a piece of code inserted on the site
What cookies are used for
In general there are cookies which can help you, by making your experience of a website better, and there are cookies which can help someone else by gathering information about you.
Cookies which keep you logged in, or remember what you had in your shopping basket tend to be quite useful in improving your web browsing experience by making things quicker and easier.
Then there are cookies which are used to track your online activity. One use for these types of cookies is to enable advertisers to place specifically tailored adverts in front of you while you surf. If you've searched for a particular product, you may have noticed that for weeks after you're still seeing adverts for it or similar products even when you visit unrelated websites. These cookies enable the tracking of your surfing habits, and help build a profile of your interests, a profile you are most-likely unaware of.