And what applies to minor crimes and trivial indiscretions applies to speech. Police officers, employers and all those others who look for offence can find remarks online they would have needed an army of spies to unearth before the invention of the internet. A drunken man makes racist remarks on Twitter about a black footballer. I am not defending racism when I say his were the kind of remarks drunken football fans make all the time. His Twitter followers denounced him. He sobered up, and was mortified by their condemnations. No matter that civil society had proved it had its own sanctions, and could shame and enforce contrition without state interference. No matter that there was no evidence that he had incited racial violence. (If anything, he had incited violence against himself.) The tabloids took up the story, his university expelled him, and the courts jailed him.

Adrian Smith, a Christian manager working for the Trafford Housing Trust, posted a link to an article about gay marriage on his Facebook page. Underneath it he typed the less than incendiary comment, "The Bible is quite specific that marriage is for men and women. If the state wants to offer civil marriages to the same sex then that is up to the state; but the state shouldn't impose its rules on places of faith and conscience." If he had said the same in his church, no one would have been surprised — indeed they would have been surprised if he had said anything else. No one outside the congregation would have known about it. The housing trust decided that because he had written online he had broken the company's code of conduct. All employers can now scan the web and pull the same trick. Because the employee represents them, they can say that an expression of a political or religious opinion is not the right of all citizens of a free society but an attempt to bring the organisation into disrepute. They demoted Smith and cut his salary from £35,000 to £21,000 — a rolling fine of £14,000 a year merely for speaking his mind.

One of the most famous free-speech cases is that of Paul Chambers, a young man who was planning to fly from Robin Hood airport to see his girlfriend in Belfast. He saw on the television news that snow had closed the airport and tweeted: "Crap! Robin Hood airport is closed. You've got a week and a bit to get your shit together otherwise I'm blowing the airport sky high!!" People make bad, bombastic jokes every day. If Chambers had bellowed it to his friends in a pub, everyone would have forgotten his words in an instant. As it was, the police arrested him, his employers fired him and the courts convicted him under a catch-all charge.