Privacy Badger is a privacy-protector and ad-blocker tool from the EFF (Electronic Frontier Foundation). Privacy Badger extension for Firefox and Chrome/Chromium.
Privacy Badger by EFF
Privacy Badger is a browser add-on that stops advertisers and other third-party trackers from secretly tracking where you go and what pages you look at on the web. It is similar to Adblock Plus or Ghostery, but different in its own ways too.
Privacy Badger is not an ad-blocker primarily. It is a privacy tool which aims to prevent non-consensual invasions of people's privacy. Just that EFF badge gives it a lot of credibility even. Privacy Badger is available as an extension for Firefox and Chrome. Get it here.