He says on his site that he wants the US to pass a “shield law,” I guess the idea must be to pass a law that explicitly says we don’t extradite for this, pass along the fines, or whatever.
It seems like inside the US, this must be constitutionally protected speech anyway. I’m not 100% sure, but it would seem quite weird if the US could enter a treaty that requires us to enforce the laws of other countries in a way that is against our constitution. Of course the constitution doesn’t apply to the UK (something people just love to point out in these discussions), but it does apply to the US, which would be the one actually doing the enforcing, right?
Anyway, bumping something all the way up to the Supreme Court is a pain in the ass, so it may make sense to just pass a law to make it explicit.