Mozilla’s latest patch to its Firefox browser blocks cookies from domains with which the user has not previously engaged in an effort to make Web browsing more transparent to users, the company said today.
With the new patch, currently only available to developers, a user visiting Amazon could still see the items s/he saved to the cart a few days earlier, functionality which is powered by cookies. But cookies from advertising networks would be blocked unless the user had previously interacted with the particular brand. Social widgets would also be barred from setting cookies unless the user had previously used them on the site in question.
“We’ve had a long running interest in fostering greater transparency, trust and accountability related to many of the cookie practices we see in the market. Increasing user concerns related to third party tracking and interest in more granular cookie handling mechanisms is driving our decision to try this patch,” said Alex Fowler, Mozilla’s global privacy and public policy lead.
Advertisers may see Mozilla’s move as a “warning bell,” according to Jules Polonetsky, director of the Future of Privacy Forum, a Washington, D.C.-based think tank that seeks to advance responsible data practices.
“We’re at an interesting turning point, the Firefox move is sort of a warning bell that if companies don’t do a better job of helping customers understand that data is being used for them, then we take a risk of them turning to technical fixes,” he said.
If users increasingly elect to turn on cookie blockers like Firefox’s, the flood of data flowing to advertising networks, merchants and Web services providers will turn into a mere trickle, potentially depriving the companies of some information that users would willingly share in exchange for improved user experience if privacy policies were clearly explained.
Using the patch, Mozilla’s Fowler visited four websites and saw 75 first-party cookies set. Without the patch, the same websites set 385 cookies, he wrote on the company’s blog. In other words, for every cookie in his cache that a savvy but not expert user could identify as belonging to one of the sites Fowler visited, there were more than five third-party cookies.