EFF is launching a new extension for Firefox and Chrome called Privacy Badger. Privacy Badger automatically detects and blocks spying ads around the Web, and the invisible trackers that feed information to them. You can try it out today:

Privacy Badger is EFF's answer to intrusive and objectionable practices in the online advertising industry, and many advertisers' outright refusal to meaningfully honor Do Not Track requests. This week, Mozilla published research showing that privacy is the single most important thing that users want from their web browsers. Privacy Badger is part of EFF’s growing campaign to deliver that privacy by giving you the technical means to disallow trackers within the pages you read on the Web.

This is an alpha release; we've been using it internally and don't think it's too buggy. But we're looking for intrepid users to try it out and let us know before we encourage millions of people to install it. If you find bugs, you can file them on github against either the Firefox or Chrome repos as appropriate.

How does Privacy Badger work?

Privacy Badger is a browser-add on tool that analyzes sites to detect and disallow content that tracks you in an objectionable, non-consensual manner. When you visit websites, your copy of Privacy Badger keeps note of the "third-party" domains that embed images, scripts and advertising in the pages you visit.

If a third-party server appears to be tracking you without permission, by using uniquely identifying cookies to collect a record of the pages you visit across multiple sites, Privacy Badger will automatically disallow content from that third-party tracker. In some cases a third-party domain provides some important aspect of a page's functionality, such as embedded maps, images, or fonts. In those cases, Privacy Badger will allow connections to the third party but will screen out its tracking cookies.

Privacy Badger in action, blocking trackers in the White House privacy policy Privacy Badger in action, blocking trackers in the White House privacy policy

Advertisers and other third-party domains can unblock themselves in Privacy Badger by making a strong commitment to respect Do Not Track requests. By including this mechanism, Privacy Badger not only protects users who install it, but actually provides incentives for better privacy practices across the entire Web.

So users who install Privacy Badger not only get more privacy and a better browsing experience for themselves, but actually contribute to making the Web as a whole better for everyone.