Hmm, well firefox could vet them so that they're not 3rd party and the user could permit to inject 'add ons' into every web page loaded. You are allowed to up

Hmm, well firefox could vet them so that they're not 3rd party and the user could permit to inject 'add ons' into every web page loaded. You are allowed to upload html/javascript dynamically (just not shared objects, jvm byte code, etc)