An anonymous reader writes "Remember when Mozilla announced that it would soon block third-party cookies by default? Not so fast. According to a new behind-the-scenes report in the San Francisco Chronicle, 'it's not clear when it will happen — or if it will at all.' Mozilla's leadership is apparently no longer committed to the feature, and the related Cookie Clearinghouse collaboration is delayed well into 2014. Who's to blame? According to Dan Auerbach, Staff Technologist at the Electronic Frontier Foundation, 'The ad industry has a ton of people, basically lobbyists, who spent a lot of time trying to convince Mozilla this was bad for the economy... I think they were somewhat successful.' Not a good showing for the purportedly pro-user organization."