Mozilla is putting the brakes on plans to block third-party cookies by default in the upcoming Firefox 22 browser. The company, which released Firefox 22 in beta on Thursday, said in a developer forum that it has postponed the controversial cookie-barring plan in order “to collect and analyze data on the effect of blocking some third-party cookies.”
The cookie-blocking patch, developed by Stanford grad student Jonathan Mayer, was designed to prevent companies from setting cookies on consumers' computers, unless consumers previously visited those companies. In general, the code would allow cookies from publishing sites, but not from ad networks.
But the patch doesn't always accurately identify companies that have relationships with consumers, according to Brendan Eich, chief technology officer and senior vice president of engineering at Mozilla. He says in a blog post that the current version of the code blocks some companies that consumers have relationships with, while also allowing cookies from companies that consumers presumably would not want to be tracked by.
“Just because you visit a site once does not mean you are okay with it tracking you all over the Internet on unrelated sites, forever more,” he writes. “Suppose you click on an ad by accident, for example.”
He says the company will have an update in around six weeks, adding that the delay should not be viewed as Mozilla “softening” its stance on privacy. “We are always committed to user privacy, and remain committed to shipping a version of the patch that is "on" by default,” he says, adding: “The patch as-is needs more work."
Mozilla's announcement in February that it intended to block third-party cookies by default drew complaints from a host of industry representatives. The Association of National Advertisers quickly slammed the decision as “extraordinarily counterproductive for consumers and business,” while IAB general counsel Mike Zaneis called it a "nuclear first strike" against the ad industry.
Several weeks ago, Lou Mastria, managing director of the umbrella trade group Digital Advertising alliance, told a Senate panel that Mozilla's plans to block cookies were one of the reasons that the industry and advocates haven't been able to agree on implementing a universal do-not-track mechanism.
All of the major browsers, including Mozilla, offer users a way to activate a “do-not-track” header, which tell publishers and ad networks that users don't want to be tracked. But there is no consensus yet about how to respond to those signals.