Surely this is just using valuable natural resources (electricity) for profit, causing unnecessary pollution as a consequence? A bit like being paid to leave your car going on high rev's 24/7? Maybe I missed something but this seems totally irresponsible.
Wouldn't there also be the risk that huge botnets will multiply the impact to natural resources and pollution by potentially millions? I haven't looked into this but it is exactly the type of thing that would suit botnet exploitation, by mob-hackers etc. I don't see how this can end well.... Please educate me if I am way off the mark.