> If you are a public company, then you signed up for SEC regulation
If you are under American jurisdiction, you signed up for SEC regulation. Private American companies, offshore companies selling securities to Americans and perhaps even foreign overseas individuals transacting for securities in U.S. dollars are each, to varying degrees, under U.S. jurisdiction.
Since the subject of this thread is potential regulation by American regulators, it is presumed that we're talking about American companies unless otherwise stated. I don't think anyone has intimated that the U.S. S.E.C. is going to investigate blockchain speculators around the world.