It's not a fallacy since there is nothing special or noteworthy about the UK. If every other country sent out such letters, then you'd have to block every country except your own. That's a fact. There are 195 countries in the world, no law office could possibly ensure you're complying with the laws of all of these countries within your own country. The laws are not even consistent, for example you violate the EU's GDPR by complying with Ofcom's demands. The UK's behavior sets a bad precedent that other small countries might follow. It's already enough having to keep up with US and EU regulatory demands, and we have to, since these are markets we can't ignore. Even just a few more small countries coming up with demands like Ofcom could create insurmountable legal problems for small companies like ours.

Let me put it another way: Would you comply with a similar letter from North Korea? From Russia? From China? If not, your attitude is hypocritical and inconsistent.

We're taking those threat seriously and have decided to block all UK IP numbers and not to do business with the UK for the time being. News that Ofcom might ignore such measures are worrying to us.