People in the US, and/or doing business in the US need to follow US law.
Yes and those offering securities in the US, regardless of their nationality of the issuer or the nature and object of the security.
Secondly, it's just as likely that the government will crack down on bitcoin itself as it is they'll crack down on bitcoin shares. If you don't think you should have any money in something that the government theoretically crack down on then you should immediately sell all your bitcoin, as the government could declare it illegal tomorrow, if they wanted.
THey can also make drinking softdrinks illegal if they want, but its not illegal now. However, selling unregulated securities to unsophisticated investors already is beyond a shadow of doubt.
So it is beyond a shadow of a doubt that the government is responsible for defining who is a sophisticated investor? I question if there is a clear definition of what constitutes a security that government assumed the authority to regulate. Video game credits would probably fit their definition. It invites a question of why regulations are not being equally enforced. The consent
of the governed authorizes government to apply force to provide for the
defense of their rights. Read the third sentence of the Declaration of Independence to understand the rights that people retain and how to address grievances.
Much of government authority comes from defining the game. If you trade USD then you must... If you want to be listed as a security then you must... If you want X then you must Y... Bitcoin is special because it is an entirely new game.