Mozilla released Firefox 79 last week which included a new feature, Enhanced Tracking Protection (ETP) 2.0. The feature blocks ad tech firms from tracking users across the web.
- ETP is able to block a new technique called ‘redirect tracking’, which advertisers have been using to circumvent browser privacy settings. This is the latest enhancement for privacy since Firefox and Chrome announced they would be removing third-party cookies.
- The feature is only available to Firefox 79 users but Mozilla plans to roll out ETP 2.0 to all users in the next few weeks.
- “Tracking poses a threat to society, user safety, and the autonomy of individuals…We’re committed to protecting users against these threats by default” Mozilla wrote on the company’s security blog.
What is redirect tracking?: The technique, employed by ad tech firms, works by forcing the user to make an “imperceptible and momentary stopover” on the ad tech firm’s site. During this redirect, a tracker is placed via first-party cookies and then stored by the company before forwarding the user back to their intended site.
Firefox’s defense: With the upgrades to ETP 2.0, Firefox automatically clears out any cookie and site data stored by trackers every 24 hours. By doing so, customers will appear as new users to the trackers on their next visit.
- Cookies from non-tracking sites will remain unaffected.
- In the case that trackers offer other services users engage with, such as search engines or social media, a 45-day exception is granted. This ensures that users can continue to have a good experience with services like Google, Facebook, Microsoft, etc.
- A more detailed technical description can be found here.
The bigger picture: The news comes in the same week that the Partnership for Responsible Addressable Media was formed. The initiative aims to “advance and protect” core functionalities, such as personalized ads and data analytics for the digital media and advertising industries.