The new Firefox policy will allow cookies presented from domains that users actually visit -- dubbed a "first-party" site -- but will automatically block those generated by a third-party domain unless the user had previously visited the cookie's site-of-origin.
The result, argued Jaffe, will not be what people expect. "The facts are that [Firefox users] will get more ads, not less, and those ads will not be tailored to their interests," he said. "They'll see untargeted ads, which will look like spam. We have to get this information to them somehow."
Mozilla has not set a Firefox release for the third-party cookie blocking, but the earliest would be Firefox 22 in late June. That edition is slated to move out of the "Nightly" channel, the roughest-edged version aimed at developers, into Aurora on April 2.
But it could be pushed to a later Firefox, or never see daylight. "As with all our new Firefox features, there will be months of evaluating technical input from our users and the community before the new policy enters our Aurora, Beta and General release versions of Firefox," said Brendan Eich, Mozilla's CTO, in an email. "This will stay in our Nightly build until we are satisfied with the user experience."
The ad industry's assault on Mozilla was not its first volley against browser makers.
Since Microsoft unilaterally decided last year to switch on the "Do Not Track" (DNT) privacy feature in IE10 -- Windows 8's default browser, which is now being pushed to Windows 7 PCs -- the online ad industry has loudly condemned Redmond. In October, the ANA called Microsoft's DNT position "unacceptable."
Work by the Worldwide Web Consortium (W3C) to come up with a DNT standard has effectively stalled over Microsoft's move and other issues, although the standards-setting group continues to meet, most recently in Berlin.
Last year, Brookman had predicted that, failing a DNT agreement, browser makers would take matters into their own hands. And that's what they've done, he said in a February post about Mozilla's decision. "Given the continued lack of an agreement on a Do Not Track standard, we think [Mozilla] made the right call."
From the ad industry's perspective, Microsoft and Mozilla are guilty of the same crime: Making privacy decisions for users. "I'm astounded, frankly, that [Microsoft and Mozilla] essentially say, 'I'm smarter than you are, we will decide for you,'" said the ANA's Jaffe.
But both Mozilla and Brookman pointed out that Mozilla's Firefox plans are no different than what Apple's Safari browser already does. By default, Safari blocks third-party cookies, and has since its 2003 debut. The iOS version of Safari has done the same since its 2007 inception.
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