In 2020, the EFF updated Privacy Badger to no longer learn from your browsing by default, as local learning may make you more identifiable to websites. In order to make this change, they expanded the scope of Badger Sett-powered remote learning. They then updated Privacy Badger to start receiving tracker list updates as part of extension updates.
Since Badger Sett automates a real browser, visiting a website takes a meaningful amount of time. That’s where Badger Swarm comes in. As the name suggests, Badger Swarm orchestrates a swarm of auto-driven Privacy Badgers to cover much more ground than a single badger could. On a more technical level, Badger Swarm converts a Badger Sett scan of X sites into N parallel Badger Sett scans of X/N sites. This makes medium scans complete as quickly as small scans, and large scans complete in a reasonable amount of time.
Badger Swarm also helps the EFF produce new insights that lead to improved Privacy Badger protections. For example, Privacy Badger now blocks fingerprinters hosted by CDNs, a feature made possible by Badger Swarm-powered expanded scanning.
You may want to opt back into local learning if you regularly browse less popular websites. To do so, visit your Badger’s options page and mark the checkbox for learning to block new trackers from your browsing.
As a compromise to avoid breaking websites, CDN domains are allowed to load without access to cookies. However, sometimes the same domain is used to serve both unobjectionable content and obnoxious fingerprinters that do not need cookies to track your browsing. Privacy Badger now blocks these fingerprinters.
There are still those who think that their browser data can be publicly used as they have nothing to hide, but it is not about blackmailing or phishing you at all. It is not only about highly selective targeting for commercial advertising, but also for governments and other shady actors to incite anger and outrage type responses to influence voting, religious based reactions, etc. It is not just advertisers who buy this data.
See https://www.eff.org/deeplinks/2023/10/privacy-badger-learns-block-ever-more-trackers