> From the client side one mitigation might be to have all extensions denied network access by default and have the user manually whitelist those in a little-sn

> From the client side one mitigation might be to have all extensions denied network access by default and have the user manually whitelist those in a little-snitch like manner. I don't think, Google has any interest in doing that. You can't either block internet access on a per-app basis on Android, even though this would close tons of information leaks, that the clunky permission system they currently have in place just can't fix. And as for the best thing to do from Google's side, that would probably be what Mozilla is doing. Sit actual human beings down to look at the code of newly submitted extensions and of extension updates. No, this does not scale, can't be automated by some algorithm, but it actually works. And it's not like it needs to scale into the millions.