> Imagine how much friction it'd require to setup such devices if everything was processed on client side or required explicit opt-in before accessing the info.

> Imagine how much friction it'd require to setup such devices if everything was processed on client side or required explicit opt-in before accessing the info. Gmail's basically parsing emails, so I don't think it would be that hard to do client-side if there was a community effort to create and maintain the parsers. That's certainly doable, because ad-block lists have some of the same characteristics and are community maintained.