Being a happy Firefox user and watching all the browser drama from the backyard. I still don't understand why people uses Chrome or Chrome variants claiming privacy things.
In 2018, Mozilla surreptitiously installed a mysterious plugin named Looking Glass to every installed browser as part of a marketing deal with the Mr. Robot TV show. Thus plugin altered websites for an alternate reality game promoting the show.
Back in 2017 Firefox Focus, one of their iOS efforts marketed as being about user privacy, collected telemetry and sent it to Adjust GMBH, a tracking/analytics company based in Germany.
Also in 2017 Firefox integrated a Cliqz plugin to recommend content in the searchbar based on your browsing history, which was sent to the Cliqz servers and theoretically anonymized. Cliqz GMBH is another German company involved in analytics/tracking, and a notoriously scummy one to boot.
I mean, I could go on. Mozilla's hands ain't clean, they make mistakes, but at least their _manifesto_ is worthy.