Ofcom is the internet censor in the UK. If someone says something deemed to be offensive the police send data requests to social media companies to get data on the offender. Gab has decided to IP block all of the UK.
My understanding is that in the UK, they do distinguish between things that are expressed in a more academic style vs more inflammatory and sensational statements like what you find on social media. ARMREG is based in the UK. ARMREG presents very controversial ideas but the style of presentation is quite conservative. This seems to give some cover (for now).