CowboyRobot writes: Despite strong advertising industry opposition, Mozilla is advancing plans to have the Firefox browser block, by default, many types of tracking used by numerous websites, and especially advertisers. "We're trying to change the dynamic so that trackers behave better," Brendan Eich, CTO of Firefox developer Mozilla, told The Washington Post. According to NetMarketShare, 21% of the world's computers run Firefox. Eich said the blocking technology, which is still being refined, will go live in the next few months. The blocking technology is based on that used by Apple's Safari browser, which blocks all third-party cookies. Advertisers use these types of cookies to track users across multiple websites. Mozilla's cookie-blocking efforts follow a Do Not Track capability being adopted by all major browsers. But the DNT effort stalled in November 2012, after advertisers stopped participating in the program, following Microsoft making DNT active by default in Internet Explorer 10. Advertisers wanted the feature to be not active by default.