The FBI doesn't have a shred of jurisdiction outside this country...
Again, who did they send them to? They can send all the subpoenas they want outside American borders and the recipient can piss on them and toss them in the trash, they're meaningless. FBI can't do shit outside this country. Anything they attempted would be tossed out on its ass in any court.
How much would you worry about a court order from China?
If they sent them to exchanges here, then it would be coinbase. I asked what other ones are there besides coinbase? If that's the only one operating on US soil, then that's just one.