Many comments here are on the premise that 4chan is "operating in"/"providing services in"/"broadcasting in" the UK, or similar.

As I understand it, _the UK_ is the one performing the importing of this content (through the backbones). 4chan is involved at no part of that pipeline other than connecting their servers to the Internet.

There are two ways in which a country could control content:

1. Through a governing body capable of regulating global content, like an Internet UN (with actual power)

2. Banning content locally via (broken) technical means

The UK is pretending that there's a third option: Telling other country's they have to abide by UK law.