Sen. Manchin's main constituent is the coal industry. Crypto-currency mining uses a fair amount of electricity. I'd guess most cryto-currency enthusiasts are also "green" enthusiasts. Manchin may want to stop this: "SolarCoin debuted last month and builds on the same technology as Bitcoin"

http://thinkprogress.org/climate/2014/02/21/3282131/solar-co...