There’s been multiple cases where non-US gambling websites have had their domains confiscated by the American government because they have American users, going back about 20 years.
Claiming jurisdiction is one thing, ensuring cooperation of the host state is another, and requires either kowtowing to the US or similar legislation, even if there is an extradition treaty.
The arguments are very similar. You could claim that only accepting fiat currency should count, but that would open a massive loophole that would be trivial to exploit