One could also argue that the power used by the vehicles themselves contributes to increased emissions.
I think the only way forward here is to generate electricity as cleanly as possible. That way we won't get bogged down in arguments about amazon's terawatt-hours being more worthwhile than those of facebook or bitcoin.
That's exactly why people advocate for carbon taxes. Instead of guilt tripping people you just add a financial tradeoff for pollution. Businesses don't understand morals but they do understand money and once you give them a profit motive they are willing to eat their polluting competitors for lunch.
I think the only way forward here is to generate electricity as cleanly as possible. That way we won't get bogged down in arguments about amazon's terawatt-hours being more worthwhile than those of facebook or bitcoin.