Alan Westin, one of the first to analyze privacy in political terms, defines information privacy as "the right of individuals, groups and institutions to determine for themselves, when, how and to what extent information about them is communicated to others."

Many people are unaware that when we go online, we leave an electronic record of our movements—and we can unwittingly provide personal information to people and organizations that track such data.

Information about online surfing habits, preferences and purchases is a valuable commodity for companies that conduct business on the Internet. Communication technologies allow personal information to be compiled from several sources, to reveal patterns in online behaviour. The collected information can be sold or traded to third parties such as government departments, law-enforcement agencies or businesses.

Electronic tracking devices such as cookies, Web bugs and "spyware" are common means of tracking our online behaviour. These devices collect information such as ISP addresses, Web sites visited, purchases made, and emails sent.

Cookies

A cookie is an electronic text file that a Web site parks on a visitor's browser. It can either be a session cookie, which expires when the visitor leaves a Web site; or a persistent cookie, which serves as a record of a user's trip to a particular Web site and allows for easier recognition on subsequent visits. When a visitor returns to a Web site that has previously given the computer a cookie, special text in the cookie program communicates with the Web site in order to present the visitor with customized information.

The use of cookies can make navigating the Web a smooth experience. But it's also a way for businesses and other organizations to track the movements of Web users, and to build up personal profiles of their behaviour, habits and buying patterns.

Web Bugs

Web bugs are small transparent graphics that are placed in Web pages or email messages. Generally used to measure the number of hits on a site or to record which sections are most often accessed, Web bugs collect detailed information about online purchases and surfing habits. They can be combined with cookies to record the types of sites visited, search terms used, and any purchases made. They can also access any personal information that visitors may submit when they register for an online service or enter a contest.

Spyware

Popular software available on the Internet, such as music sharing programs, may come bundled with other software—which has embedded instructions to gather personal information. Such software, called spyware, tracks Web sites visited by a user, and uses this information to build a profile. Some spyware can even collect personal information from forms filled out online.

The main concern with these types of online surveillance is that they usually happen without the user's knowledge or consent. Privacy advocates stress that online marketing companies should always obtain a user's consent before giving cookies to a computer, or gathering any information about a visitor's online practices.

In response to this concern over electronic surveillance, many industry organizations and Internet businesses have now drafted privacy policies. These policies are intended to explain why and how information is collected, used and stored.