Technically speaking, if the mining operations are completely outside of the United States, none of the three letter agencies have any jurisdiction. Think of it from the perspective of KnC cloud-mining. You can only purchase into that if you are outside of the EU, avoiding infractions against EU laws (and the related liabilities). If any of the operations of GH are inside the U.S., then there could be issues with that, but there would have to be a measurable and or significant percentage of the operations inside the U.S. for the various agencies to take notice of it. In many cases, "size" does matter. The cost basis of pursuing any litigation of any entity must be warranted for such actions. Moreover, when the general public have access to the purchase, sale or general trade of the tokens, then it certainly falls within their jurisdiction, but this is not presently the case, as far as I have seen. The "shares" represent ownership of a small group of people involved in a private "venture" that is registered in another country outside of both the U.S. and the EU. The purchase and sale of GHcoin is done in a private environment of registered forum members. You cannot sell GHcoin outside of this environment at present. As long as that remains the case, there is little to no risk of any EU or US entity intervening. The use of the term "shares" may also not be accurate in this case. The SEC has requirements for registration of "shares" of any public U.S. incorporated entity. In the EU, there are similar requirements. For private corporations, the requirements are much less, when the composition of the shareholders has one or more things in common with each other. An S-corporation in the U.S. also has "shares" of the company, but they are not traded or exchanged on any recognized stock exchange. Therefore, such shares are of no interest to the SEC, until such time that these shares are sold, in any capacity, to public persons who do not share at least one common attribute with the company owners/partners. You can bring new people into the corporation, selling them shares of ownership, as long as they have something in common with everyone else in the corporation, such as all members being attorneys, dentists, doctors, etc. Companies domiciled in tax havens must only comply with the laws of that specific country. These laws are generally quite loosely structured though.
Finally, on the SEC website, there are sections relating to "private investment clubs." Presently, the SEC does not require private investment clubs to register. However, in the U.S., if the investment group is all located or incorporated in one specific state, there may be state laws that require the registration of such groups with state revenue agencies. Each state is different in this regard however.
It is all so complicated anymore. 
