by Bill Snyder

Firefox Wants to Eat Obnoxious Third-Party Cookies

Feb 25, 20134 mins
Consumer ElectronicsPrivacy

An upcoming version of Mozilla’s Firefox browser will block third-party Internet cookies served by online advertisers. That's great for people who don't want to be tracked, but online advertisers are up in arms over the change.

There are good Internet cookies; and there are bad Internet cookies. Say you subscribe to When that site places a cookie in your browser, it tells the site that you’re a subscriber and can see all the content you want. Nothing wrong with that. But do I really want Chobani Greek Yogurt or American Express, two companies advertising on the home page today, tracking me? Nope.

Third-party cookies are used by advertisers to figure out where you go on the Web and what advertising is most likely to open your wallet. That’s why you’ll notice personalized ads following you from website to website, annoying you and possibly gathering information that you don’t want collected. Not everyone cares, but many people do, which is why Mozilla, Firefox’s creator, has decided to block-third party cookies by default in an upcoming version of the browser.

Apple’s Safari has blocked third-party cookies for some time, and other browsers give you the option to block them. But doing so in Google’s Chrome or Microsoft Internet Explorer takes a number of steps and in the case of IE, the rules for blocking cookies are quite confusing.  I doubt that many users even know the option is there anyway.

Stanford graduate student Jonathan Mayer, who is also a contributor to the Firefox codebase, explains the new policy in a blog post here.

From that post:

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.

The online advertising industry is really unhappy about this. Mike Zaneis, senior vice president and general counsel for the Interactive Advertising Bureau, calls the new policy “a nuclear first strike against ad industry.” What a bozo!

The new cookie policy will be probably be implemented in version 22 of Firefox, which is due in June, according to Mayer. In the meantime, here’s how you can block third-party cookies today.

In Google Chrome, click the tools icon in the upper right-hand corner—it looks like three horizontal lines on top of each other—then go to Settings, Advanced Settings and look for Content Settings under the Privacy heading. Click to open that option, and you’ll see a box you can check to block third-party cookies.

In IE, go to Tools, Internet Options and click the Privacy tab. From there, it gets complicated. You’ll see a slider that lets you adjust the cookie options from “accept all cookies” to “block all cookies.” In most cases blocking all cookies is not a good idea, because some websites, such as online-banking sites, won’t work well without them. The mid-range options have to do “a compact privacy policy,”  developed by some obscure committee.  Wikpedia has a decent entry on the subject:

“The Platform for Privacy Preferences Project (P3P)is a protocol allowing websites to declare their intended use of information they collect about web browser users. Designed to give users more control of their personal information when browsing, P3P was developed by the World Wide Web Consortium (W3C) and officially recommended on April 16, 2002. Development ceased shortly thereafter and there have been very few implementations of P3P.”

That basically means IE’s policy on third-party cookies is bull (you know what), and Microsoft has recieved a lot of deserved flack for it.

In current versions of Firefox you start at Options and drill down to disable third-party cookies. Here’s a link that explains the process very well.