The "Do Not Track initiative has been endorsed by the FTC, and the privacy setting is already available to the users of the three of the four most popular web browsers: Firefox, Internet Explorer and Safari, while Chrome users need to download and use an official Do Not Track add-on.
"When you turn on DNT in your browser, we stop collecting the information that allows us to tailor Twitter based on your recent visits to websites that have integrated our buttons or widgets," Twitter explained in a help file. "Specifically, we remove from your browser the unique cookie that links your browser to visits to websites in the Twitter ecosystem. We then cannot provide tailored suggestions for you."
The do not track header that requests web applications to disable their tracking of a user is currently being standardized by the World Wide Web Consortium.
At the time being, websites are not required to comply with the user's do not track request, and Twitter is the first of the large Internet companies out there who supported the initiative.