Mozilla is preparing to offer a more sensitive approach to how it implements the "Do Not Track" setting in its popular Firefox browser.

The whole "Do Not Track" issue sparked lots of controversy in the past few years, and the tech world is constantly toying with various solutions.

Firefox 21 beta now introduces more user choices for the "Do Not Track" header. This header first debuted in Firefox 4 two years ago, as a way to signal websites not to track users who activated the "Do Not Track" option. Until now, implementations of this setting included only "On" or "Off." Firefox lead privacy engineer Sid Stamm describes these options as "user says nothing" and "user says don't track."

According to Firefox security engineer Tom Lowenthal, however, the controversial "Do Not Track" actually has three states:

• DNT:0, which means "I consent to being tracked;"
• DNT:1, which means "I object to being tracked;"
• Neither, if the user doesn't send a signal.

If the user doesn't send a signal, the browser will not communicate any of those settings (DNT:0 and DNT:1).

"When DNT is off, it doesn't mean 'please track me,' explains Lowenthal. "It means that the user hasn't told the browser their choice yet. According to the security engineer, when first installing Firefox the browser is set to neither option, which means the choice is entirely up to the user.

It remains unclear, however, just how websites will react to this implementation. In theory, websites that don't receive any "Do Not Track" preference should not track users. Websites are still issuing cookies that follow users around the web, and this practice long precedes the DNT concept. In other words, Firefox' attempt sounds like a good idea, but it may not be able to change how the web currently works. Users can adjust their DNT preferences under Options > Privacy.

Meanwhile, upcoming versions of Firefox will block third-party tracking cookies by default due to the Firefox 22 Aurora build. That option should be available in around July. Check out the full release notes for Firefox 21 Beta at this link.