If a country wants to enforce some kind of rules, they will have to apply them to the countries residents, because its the resident that go out on the net and conduct the behavior, not the other way around.
This has been common sense for a long time now. Everybody is going crazy/mad. Must be some seriously narcissistic people running the UK.
Simply by sending some threating letters to payment processor management. It was done by few hundred fanatics who want to censor what content everyone is allowed to access.
Since this is possible, there not enough resistance and UK government have much more resources we'll all have to live with this.