Unknown Mozilla dev addon "Looking Glass 1.0.3" on browser

Many people seem to be shocked because Mozilla installed an add-on automatically. In my opinion, it doesn't really matter since the code is coming from Mozilla - they're building the whole browser, so they could introduce functionality anywhere. If someone distrusts their add-ons, why trust their browser at all?

The main question is what behavior is being introduced. I haven't researched deeply, but apparently the add-on does nothing until the user opts-in on studies.

> I haven't researched deeply, but apparently the add-on does nothing until the user opts-in on studies.

It adds some css to a list of words:

https://github.com/gregglind/addon-wr/blob/da464ac8f1c3b0894...

The extension only starts up if the config option "extensions.pug.lookingglass" is set to "true" though:

https://github.com/gregglind/addon-wr/blob/da464ac8f1c3b0894...

(It defaults to "false.")

We already have a mechanism for disabling or enabling addons, it's not installing them in the first place. Why on earth would we put it to addons to self-police them.

It's behind a preference flag because it's installed automatically, and Mozilla's the only one who can do that. That's also why there's a lengthy approval process before such an addon can be pushed out:

https://mozilla.github.io/shield-studies-docs/study-process/