In the context of the internet, cookies are little bits of data stored by web browsers that allow them to track visitors. They have many useful purposes. Commerce sites can keep track of what you have put in your shopping cart; sites can store your language preferences and login information; and so forth. This site uses a cookie so that those leaving comments only need to enter their name and email address once. Of course, cookies can also be used in more malicious ways, such as keeping track of what sites you visit without your approval.
Clearing out cookies is something that can nominally be done by all browsers. Unfortunately, this only applies to cookies of the conventional sort. Now, there are a multitude of ways through which browsers can store information through which to identify a particular computer and browser. As a demonstration of that, the ‘evercookie’ developed by Sami Kamkar stores information in eight different ways. Furthermore, it is able to regenerate any of the information if the user deletes it, provided all eight are not deleted simultaneously.
Kamkar’s intention is to show how tracking technology has outpaced the privacy features in browsers. The loss of anonymity is one of two big changes that have taken place on the internet, since the heady days of its birth. The other, of course, is the increasingly intrusive role played by governments.