Yet, the US government successfully indicted and got the four founders to surrender [1] (two of whom were non-US citizens).
They can definitely claim jurisdiction if American users were affected in the scheme.
1 - https://www.coindesk.com/markets/2021/03/15/bitmex-founder-b...
Why? These ~~marks~~ investors wanted free unregulated finance on the blockchain, and they got it. Where's the crime?
People who spent money on Terra/Luna knew it was a cryptocurrency that used magic computer maths to make numbers get bigger (until number got small), same as all the other cryptocurrencies.
So no, it's still a ponzi, and no, most people had no idea.
https://www.politico.eu/article/wife-of-us-diplomat-anne-sac...
At core, as with most things, it's unfortunately a question of power, not legality ...
If they had just done shit by the book they would have had him on US soil with no problems at all.
FWIW I don't agree that he -should- be able to be extradited. Just stating the fact that if the US had just not screwed the pooch they would have been successful in doing so.