With what? I _do_ care about running random plugins in my browser that update in the background. There's nothing stopping a malicious plugin from scraping stuff out of your email, and I feel like _that_ is a legitimate security concern!
>I _do_ care about running random plugins in my browser that update in the background.
Then turn that function off [1]. There's no more security threat from well-known browser plugins from Mozilla's site than well-known packages from your OS's apt repo. And both are open source.
