[ris]

> It's as immoral as advertising, maybe even less.

You've actually managed to convince yourself that, haven't you?

It isn't because:

1: the user is paying for the electricity being wasted by you. A tab left open could be significantly detrimental.

2: it will cause real problems for mobile users who will be wondering why their battery's flat.

[joaojeronimo]

We -really- don't want to seem sketchy and immoral. We plan to stop computing after a certain amount of time (still to figure out, so far we don't have that many tasks running for it to be significant), and we completely block mobile phones and tablets while the Battery Status API isn't present in all devices (http://www.w3.org/TR/battery-status/ only Firefox implements it currently)