Because he's in the US, the SEC can force him to stop being a witness on any Hive fork that still has HBD.
Not sure how true that is.
They can stop nodes from running in USA.
Very difficult to stop them from running elsewhere.
Plus people can move and even renounce citizenship in extreme edge cases.
Their idea of what "in USA" is can be flexible. And US persons can still be held liable for what they do outside of the US.
Yes, of course people can move and renounce citizenship if needed.