The amount of resources required to load a blob of json, some images and do a shitty js callback matroska dance is relatively well understood and accepted as a necessary evil by those that don't/can't block such things. Yes there are bad actors that will churn through your mobile data while your phone is locked, endlessly reloading shitty video ads, but who knows how well miners will be coded or perform.

I'm betting on hearing some horror stories fairly soon as the first gen is rolled out.