Widespread release of the blocking technology remains months away. But officials at Mozilla, the nonprofit group that makes Firefox, spoke confidently Wednesday about the growing sophistication of tools they are building to limit the placement of “cookies” in users’ browsers.
These bits of code, often placed by data collection companies that users have never heard of, allow the companies to learn what sites a browser visits over months or even years. Firefox would still allow cookies if users were to give a Web site express permission, or if users were to visit a site regularly — as is common with shopping, social-media or news sites.
“We’re trying to change the dynamic so that trackers behave better,” said Brendan Eich, chief technology officer for Mozilla.
The Firefox browser is used by about 20 percent of the world’s desktop computers, according to NetMarketShare.
The blocking technology that Mozilla is developing borrows heavily from Apple’s Safari browser, which blocks all “third party” cookies, meaning tracking codes from sites that users do not intentionally visit.
Mozilla also plans to add limits on cookies placed by sites that users intentionally visit, such as Facebook, to prevent tracking when users sign off and go to other sites. Mozilla plans to test and further refine its technology over the next few months before making it available to all users. No release date has been set.
“This is welcome news from Mozilla,” said Sen. John D. Rockefeller IV (D-W.Va.). “It proves there’s a market for giving consumers strong privacy protections . . . when online advertisers fall short.”
Randall Rothenberg, president of the Interactive Advertising Bureau, said the changes could disrupt Internet commerce, especially damaging smaller Web publishers that rely on the revenue brought by targeted advertising. He expressed hope that the industry could still persuade Mozilla to abandon or at least significantly alter its plans before widespread release. (The Washington Post Co. is a member of the Interactive Advertising Bureau.)
“There are billions and billions of dollars and tens of thousands of jobs at stake in this supply chain,” said Rothenberg, who called the browser makers “oligopolies” with excessive power to make decisions affecting the workings of the Internet. “It should be done with stakeholders’ input.”