Original URL: https://www.theregister.com/2013/02/25/firefox_cookies_policy/

Firefox to spit out third-party cookies

Mozilla says Apple's got it more or less right

By Simon Sharwood

Posted in Software, 25th February 2013 02:25 GMT

The Mozilla Foundation has set up camp alongside Apple in the “cookies are bad” section of the Internet, decreeing that three versions hence its flagship Firefox browser won't accept cookies from anyone other than the publisher of websites it visits.

That version will be number 22 and is due for release on June 25th, 2013. That leaves the world's web publishers a decent amount of time to adapt to the regime devised by Stanford graduate student Jonathan Mayer, who is also a contributor to the Firefox codebase and explains the new policy in a blog post here.

The post explains the new cookie policy enforced in the browser as follows:

Q: How does the new Firefox cookie policy work? A: Roughly: Only websites that you actually visit can use cookies to track you across the web. More precisely: If content has a first-party origin, nothing changes. Content from a third-party origin only has cookie permissions if its origin already has at least one cookie set.

Mayer points out that this plan is very similar to that employed for nearly a decade in Apple's Safari browser, so should not set alarm bells ringing.

The practical effect of the change will be to stop advertising and networks using cookies when users visit pages containing their ads or widgets. Many users will appreciate that, as it will make it harder for their online activities to be mined, analysed and turned into “helpful” ads or other content.

Developers may need to do a little work to cope with the change, as Mayer writes "If a user does not seem to have intentionally interacted with your content, or if you’re uncertain, you should ask for permission before setting cookies. Most analytics services, advertising networks, and unclicked social widgets would come within this category."

That could mean occasional problems for users. Some folks on Usenet group mozilla.dev.privacy feared for users of early Firefox builds who visit websites that expect untramelled cookie-dispensing rights.

Overall, however, the commenters appreciated the new policy which, once it comes into force will mean nearly 30 per cent (see browser share stats here) of web browsing will be done with browsers hostile to third-party cookies.

Firefox may, however, offer an out for all concerned, with Mayer's post suggesting the new policy could exempt sites that sign up to the Do Not Track proposal. Mayer maintains that effort's web site.. ®