I'm not advocating calling them, but FWIW there already is an authority who could be regulating these guys. IIUC GHash are registered in London, so they'd be under the control of the UK's Financial Services Authority.

If you're just an ordinary node in a p2p network it would be none of their business, but once you're controlling over 50% of the network it's not really obvious that you're different to any regular, centralized payment processor like PayPal. In which case you need to be doing AML/KYC and all kinds of other expensive, bureaucratic things that would seriously erode your competitive advantage...