OFFENCE has several related definitions and so, for that matter, does police. That’s not usually very important because a combination of context and common sense will tend to make it clear which use is intended. It would be problematic only if somebody were incapable of understanding everyday speech or the basics of the law. Even that probably wouldn’t matter unless it were some body – such as a police force – given particular powers on the grounds that it understood such basic distinctions.

Unfortunately, South Yorkshire Police showed that it didn’t earlier this week on – where else? – social media, that universal solvent for disclosing illiteracy, wrongheadedness and megalomania.

The humdinger sent out by @syptweet on Twitter read: “In addition to reporting hate crime, please report non-crime hate incidents, which can include things like offensive or insulting comments, online, in person or in writing. Hate will not be tolerated in South Yorkshire. Report it and put a stop to it.” Inevitably, the payoff to this drivel was a fatuous hashtag of their own devising: #HateHurtsSY.

Presumably, @syptweet expects its followers to report anyone who tweets, says or writes something rude, such as “South Yorkshire Police are idiots”, which should keep them busy, since tens of thousands of people have done just that. Not very surprisingly, since a sizeable chunk of Twitter is expressly employed by its users to give offence, insult, express their hatred of or otherwise mock and denigrate people or ideas with which they disagree.

As its tweet indicates it is at least dimly aware, it is not usually an offence to give offence. It seems to be unaware, however, that it is not the job of the police to police things that are not crimes. Calling, for example, the Reverend Canon Dr Alan Billings, Labour’s Police Commissioner for South Yorkshire, who was wheeled out to support the tweet, “idiotic” is not against the law. For one thing, it’s true. And for another, vulgar abuse is not defamatory.

There’s something to be said for discouraging rudeness, verbal abuse and incivility. But we do so not through the courts, but courtesy. It’s informal social mechanisms – parenting, the classroom and other structures that encourage respect and tolerance, of which manners are the most obvious example – that police most offensive behaviour. The word police, after all, comes from the same source as polity.

There are, though, specific laws against giving certain sorts of offence, even if free speech purists, the American First Amendment and Milton’s Areopagitica argue that there shouldn’t be. Cases of abuse on the basis on race, sexuality or religion are seldom out of the news, and we expect the police to act where the law has been broken. But the corollary of having such laws, created by a democratically elected legislature, is that we expect the police not to act when no laws have been breached.

Other forces have been guilty of similar idiocies. You may remember that a couple of years ago, the Greater Glasgow division of Police Scotland sent out a tweet that declared: “Think before you post or you may receive a visit from us this weekend”, and telling people to consider whether something was “true, hurtful, illegal, necessary and kind” before tweeting it.

This may be what your parents encouraged you to think before saying something, but with the exception of the third of them, none of it is any business of the police unless you’re living in a police state. Indeed the definition of a police state would be one in which uniformed rozzers turned up to your house at the weekend to menace you for something that isn’t a crime.

In a further demonstration of the superiority of manners over clod-hopping coppers, your parents will also have told you that “sticks and stones may break your bones, but words can never hurt you”. Of course, words can and do hurt people, but the message of that instruction to toddlers is that they need to acquire a sense of proportion, and that there is no such thing as a right not to be offended.

Much of Twitter is a dunce’s playground in which obsessive cranks and grievance-mongers deliberately set out to find innocuous things by which to be offended. One recent example – which had the amazing effect of generating sympathy for Jamie Oliver, a figure of widespread derision since he started banging on about banning turkey twizzlers and Coco Pops – was the accusation that marketing a brand of ready-meal rice was a form of racist cultural appropriation. No sane person, though, could take that seriously, even if South Yorkshire jots it down as a “non-crime” incident.

Context does matter, however, as a Twitter user called Arieh Kovler pointed out when Jon Lansman, the chair of Momentum, tried to claim that graffiti at the Warsaw Ghetto reading “Free Gaza and Palestine” wasn’t necessarily anti-Semitic. Kovler correctly responded that saying “Stop Isis murders” isn’t Islamophobic, but it would be if you spray-painted it on the side of a mosque.

Cases of racial abuse, physical threats and defamation are a different matter from cases of ordinary abuse, which is why we have laws about them. Yet, while it may not cheer you up to be told online that you’re an idiot, or heartless, or a class traitor or whatever else some troll wants to chuck at you, nothing need be done about it.

Besides the sinister, Orwellian implications of South Yorkshire Police’s attitude, though, there is also their sheer gall in focusing on “non-crime” incidents, when that particular force’s record on ignoring actual, profoundly damaging crimes is probably the worst in the United Kingdom.

These aren’t just the people responsible for the Hillsborough cover-up, the appalling failure to deal with organised gangs of child rapists in Rotherham and televising the arrest of Sir Cliff Richard (released without any charge); they’ve also presided over a rise of 19 per cent in overall crime, a 38 per cent increase in both robbery and violent offences, a 45 per cent rise in possession of weapons and a 72 per cent rise in public order offences.

Naturally, South Yorkshire Police blame funding cuts. Yet they can fund social media programmes telling people to report things that aren’t crimes, so that they can waste time and resources investigating them. I think we’re entitled to be rude about that.