Mozilla Needs More Time Before Blocking Third-Party Cookies By Default

After much public discussion of the issue, Mozilla has decided to postpone blocking of third-party cookies by default in the next version of Firefox. As noted in this post, the Internet Advertising Bureau (IAB) had raised a major stink over the issue, citing "the impact the ban would have on small Internet publishers, which depend on such cookie technology to sell advertising to niche audience segments." According to Mozilla's Brendan Eich, though, Mozilla just needs more time to implement the technology.

Eich, Mozilla's CTO and senior vice president of engineering, writes in a blog post:

"There are many conflicting claims about how this patch will affect the Internet. Why debate in theory what we can measure in practice? We are going to find out more and adjust course as needed...We have heard important feedback from concerned site owners. We are always committed to user privacy, and remain committed to shipping a version of the patch that is 'on' by default. We are mindful that this is an important change; we always knew it would take a little longer than most patches as we put it through its paces. For those who read this as Mozilla softening our stance on protecting privacy and putting users first, in a word: no."

According to Randall Rothenberg, President and CEO of IAB, in a statement: “This move will not put the interest of users first. Nor does it promote transparency or ‘move the web forward’ as Mozilla claims in its announcement. It will not advance Mozilla Corporation’s objective, as stated in its bylaws, of ‘promoting choice and innovation on the internet,’ but will, instead, impede both."

Mozilla had planned to release the third-party cookie blocking as "on by default" in Firefox 22, but it now looks like the scheme will take more time. In particular, Eich has pointed out that false positives and false negatives can arise when trying to determine which kinds of Internet content should be blocked.

Firefox won't be the first browser to block cookies by default, once the kinks are worked out. Apple's Safari browser already does so.