[ksala_]

If you limit yourself to the recommended ones they're supposed to be reviewed by a human and subject to some amount of guidelines - https://support.mozilla.org/en-US/kb/recommended-extensions-... and https://extensionworkshop.com/documentation/develop/build-a-...

Personally I do try to limit the amount of them I run, stick with recommended and take at least a glance at the source from time to time, but it would not defend against version updates or good efforts to obfuscate bad code. I do feel at least somewhat confident that for recommended extensions with substantial usage the internet would surface funny business quite quickly.

But yes, I would love for some independent third party to have some review program! Unfortunately it's not clear how it would be funded.

[itvision]

Not only that, trustworthy extensions normally have serious well-known developers behind them which decreases the risk of stumbling into something malicious.

To this date not a single extension which has been marked as recommended by Mozilla was found to contain malware.

Google on the other hand while being 1000 times richer has none of it.