TL;DR: With Firefox 56, Mozilla combined Firefox Health Report and Telemetry data into a single setting called “technical and interaction data”, which was then enabled by default. This data was then shared with advertising partners on a de-identified or aggregated basis.
I actually wanted to help make Firefox a better product. 🤷
Understood. I always felt that if it crashed in bizarre ways I’d send the crash report or something - open a ticket, whatever, but wholesale data gathering was never ok.