According to several reports, including one in the Wall Street Journal, a forthcoming version of Safari released to developers includes an option that lets users prevent cookies from tracking their browsing behavior. The browser is part of a test version of Mac OS X Lion.
Do-not-track and similar privacy options have been a large part of the public discourse about security in web browsing. Congress recently introduced a Do Not Track Me Online bill that would allow consumers to opt out of online tracking. It would work a lot like the Do Not Call registry, which allows consumers to opt out of telemarketing phone calls. And the FTC has been exploring do-not-track options since last year.
Major web browsers have preempted them by adding do-not-track features. Firefox 4 led the way, allowing users to opt out of advertising-related tracking.
Internet Explorer 9 followed suit with an option called "Tracking Protection" that allowed consumers to disable third-party ad software from reporting on their activities.
Google has released a Chrome extension called Keep My Opt-Outs, a "one-step, persistent opt-out of personalized advertising and related data tracking." So far, the company hasn't announced any plans to include a native no-tracking feature.