"When America’s vice-president accuses Europe of failing to protect free speech, the obvious retort is that he is a hypocrite."

But just because he is a hypocrite does not mean he is wrong. Europe really does have a problem with free speech.

All European countries guarantee a right to free expression. However, most also try to limit the harms they fear it may cause. This goes well beyond the kinds of speech that even classical liberals agree should be banned, such as child pornography, leaks of national secrets or the deliberate incitement of physical violence. It often extends to speech that hurts people’s feelings or is, in some official’s view, false.

Britain’s police are especially zealous. Officers spend thousands of hours sifting through potentially offensive posts and arrest 30 people a day. Among those collared were a man who ranted about immigration on Facebook and a couple who criticised their daughter’s primary school.

Vaguely drafted laws that give vast discretion to officials are an invitation for abuse. Countries where such abuse is not yet common should learn from the British example. Its crackdown was not planned from above, but arose when police discovered they rather liked the powers speech laws gave them. It is much easier to catch Instagram posters than thieves; the evidence is only a mouse-click away.

"The aim of hate-speech laws is to promote social harmony. Yet there is scant evidence that they work. "

Before long, this hampers public debate. It is hard to have an open, frank exchange about immigration, say, if one side fears that expressing its views will invite a visit from the police.

"They should start by returning to the old liberal ideas that noisy disagreement is better than enforced silence and that people should tolerate one another’s views."