Mozilla begins baking new patch to kill tracking cookies

Mozilla has begun to experiment with a new patch for Firefox, which changes whether cookies from third parties are allowed.

Citing Safari as its driving force behind the new approach, the patch will require users to "directly interact with a site or company for a cookie to be installed on their machine".

Currently, a site might call upon elements from other sites, such as advertising units, which in turn store cookies on the user's computer. These can then be recalled at a later date or time to gain an insight into user habits.

Mozilla's new patch means that these third party cookies will not be permitted on the user's computer unless they take the time to visit the third party site directly.

Mozilla Global Privacy and Public Policy Leader Alex Fowler has been testing the release and found that in a morning's worth of browsing a few news sites, the new patch blocked over 300 third party cookies without any ill effect.

"I cleared all my cookies before visiting these sites, and then re-performed this process several times as I wanted to verify that, in fact, four sites did lead to over 300 cookies from more than 100 companies I had not visited. Display ads and sharing widgets on the sites worked fine, and as I clicked on them, the various parties involved were able to set cookies," he wrote on the Mozilla privacy blog.

The new patch is currently only available in the early developer builds of Firefox, and Fowler expects it will take several months of community and user feedback before it makes an appearance in the beta and general releases of Firefox.

Those wishing to test the early build can download the "Firefox Nightly" build.