HTTP Cookie - Privacy and Third-party Cookies

Privacy and Third-party Cookies

See also: Do Not Track

Cookies have some important implications on the privacy and anonymity of Web users. While cookies are sent only to the server setting them or the server in the same Internet domain, a Web page may contain images or other components stored on servers in other domains. Cookies that are set during retrieval of these components are called third-party cookies. The standards for cookies, RFC 2109 and RFC 2965, specify that browsers should protect user privacy and not allow third-party cookies by default. But most browsers, such as Mozilla Firefox, Internet Explorer, Opera and Google Chrome do allow third-party cookies by default, as long as the third-party website has Compact Privacy Policy published.

Advertising companies use third-party cookies to track a user across multiple sites. In particular, an advertising company can track a user across all pages where it has placed advertising images or web bugs. Knowledge of the pages visited by a user allows the advertising company to target advertisements to the user's presumed preferences.

Website operators who do not disclose third-party cookie use to consumers run the risk of harming consumer trust if cookie use is discovered. Having clear disclosure (such as in a privacy policy) tends to eliminate any negative effects of such cookie discovery.

The possibility of building a profile of users is considered by some a potential privacy threat, especially when tracking is done across multiple domains using third-party cookies. For this reason, some countries have legislation about cookies.

The United States government has set strict rules on setting cookies in 2000 after it was disclosed that the White House drug policy office used cookies to track computer users viewing its online anti-drug advertising. In 2002, privacy activist Daniel Brandt found that the CIA had been leaving persistent cookies on computers which had visited its website. When notified it was violating policy, CIA stated that these cookies were not intentionally set and stopped setting them. On December 25, 2005, Brandt discovered that the National Security Agency (NSA) had been leaving two persistent cookies on visitors' computers due to a software upgrade. After being informed, the National Security Agency immediately disabled the cookies.

Read more about this topic:  HTTP Cookie

Famous quotes containing the words privacy and, privacy and/or cookies:

    The emphasis must be not on the right to abortion but on the right to privacy and reproductive control.
    Ruth Bader Ginsberg (b. 1933)

    The East is the hearthside of America. Like any home, therefore, it has the defects of its virtues. Because it is a long-lived-in house, it bursts its seams, is inconvenient, needs constant refurbishing. And some of the family resources have been spent. To attain the privacy that grown-up people find so desirable, Easterners live a harder life than people elsewhere. Today it is we and not the frontiersman who must be rugged to survive.
    Phyllis McGinley (1905–1978)

    O how terrible it must be for a young man—
    seated before a family and the family thinking
    We never saw him before! He wants our Mary Lou!
    After tea and homemade cookies they ask What do you do for a living
    Gregory Corso (b. 1930)