Do Not Track (DNT) is a browser setting that sends a message to websites and advertising networks requesting that they don't track the user. Firefox, Internet Explorer and Safari provide DNT settings.
To select the DNT feature in Firefox, click "Tools" in the menu bar and click "Options" at the bottom. Click the "Privacy" icon at the top and select "Tell websites that I do not want to be tracked." Click "OK."
Although websites are not legally required to respect the DNT request, it does send a clear message about the user's wishes. Ryan Singel, writing in Wired, says that selecting the DNT feature could be like signing a petition: "If enough people do it, the thinking goes, it will give lawmakers and privacy advocates more ammunition to push for change."
Privacy advocate Christopher Soghoian developed the idea behind DNT settings as an online version of the Do Not Call List. Critics of DNT settings and similar privacy measures argue, however, that the ability to track users is what enables website personalization, which improves the user experience, and targeted advertising, which helps to pay for a great deal of online content.