Does HN operate in the UK because I can access it here? Should they be subject to UK law?

If so should the government be allowed access to non-nationals outside the country? How about if a non-national is inside the country communicating with those outside? How about if those folks are journalist reporting where journalism is illegal (see Russia's laws on "fake news" on Ukraine).

I'm not saying your point of view is wrong, but I think its easy to jump to that conclusion as this is probably the least sympathetic case to set principle. But this _does_ set principle.

If eg. Iran requested IP addresses from Pornhub (Aylo?) for all the visitors from iranian ip addresses who have viewed a gay video there, people would be changing their view pretty fast.

They might get "visitors" from UK, but so do "coffeeshops" in amsterdam.