Twitter has implemented the Do Not Track header on its site, giving users the option of telling the site that they do not want to be tracked across other sites on the Web. The implementation is being done through the DNT technology in the Firefox browser. Twitter also updated its privacy policy to give users more information on the kind of data they collect and how users can change that. The Federal Trade Commission and other organizations have supported the use of DNT as a way to give consumers the ability to opt out of such tracking.
Source: https://threatpost.com/twitter-implements-do-not-track-051712/76579/