When the Irish comedian Graham Linehan arrived at London Heathrow Airport this past weekend, he was greeted by five armed British police officers who arrested him for — get this — three rude tweets.

Or, as Linehan wrote on his Substack, “I was arrested at an airport like a terrorist, locked in a cell like a criminal, taken to hospital because the stress nearly killed me, and banned from speaking online — all because I made jokes that upset some crossdressers.”

Whether or not you find his words offensive, it’s hard to disagree with Harry Potter author J. K. Rowling, who tweeted, “This is totalitarianism. Utterly deplorable.”

Surely, many Americans reading this must be thinking, this was some terrible mistake. A one-off, as the British might say.

Actually not. It’s more like standard operating procedure. The British writer Ed West has compiled an illuminating list of Britons prosecuted for tweets deemed offensive, noting that “the vast majority of these cases involve people who have offended progressive norms, or those who are seen as being enemies of the progressive alliance.”

There are more than 30 arrests per day, 12,000 over the course of a year, typically on vague charges of inciting violence, for offensive messages and jokes in tweets or WhatsApp chats.