[jimbobthrowawy]

Telemetry and "studies" are both checkboxes in the privacy section of firefox's preferences.

I usually turn both off right after changing the default search engine and disabling search suggestions, when I setup a new install.

[marginalia_nu]

Turns out this only turns off some of the telemetry. Turning it off completely is not entirely trivial.

https://github.com/K3V1991/Disable-Firefox-Telemetry-and-Dat...

[Dalewyn]

Mozilla claiming to be the champions of privacy (among other virtues) makes this arguably worse than Google, Microsoft, et al. because they're at least upfront about their telemetry.