[kuschku]

The official response — I asked — isthat by downloading dev or nightly you "automatically opt-in" into telemetry, because no one would download these "if they didn't want to help developing Firefox".

I've simply replaced all URLs in abou:config with https://example.invalid/, that makes sure telemetry is off.

[mdellabitta]

Interesting. Too bad Tracking Protection doesn't apply to Mozilla as well. ;)

[Sylos]

Do you remember when you asked that, roughly?

The DevEdition used to just be a dub for Aurora, a.k.a. the Alpha channel. And from that viewpoint it does sort of makes sense to enforce telemetry, as that's the whole point of providing Beta/Alpha/Nightly builds. (Not sure, if it really needs to be enforced, but it does cost them money to provide the download infrastructure for all the people using those builds and if they don't get usage data back, that's costing them money.)

With the Alpha channel gone (the DevEdition is now based on the Beta channel) and the DevEdition really being specifically built for webdevs, it does not make sense to enforce telemetry there, and it might very well just be an oversight that they haven't changed that in the DevEdition build.