This newspaper loves Twitter and everything about it. It expands people's capacity to delight in the virtual company of others, to share wit, news, esoteric information and pictures of cats. And the same rules should apply to it as to any other form of human interaction. As Sally Bercow, wife of the Speaker of the House of Commons, recently discovered, Twitter is not exempt from the law of defamation. People should be careful making, spreading or drawing attention to damaging claims about others that may be untrue.
Twitter and its users are still learning, however, how to deal with threatening behaviour. This has been a problem since soon after Twitter took off four years ago. Last year, Frank Zimmerman was given a suspended sentence for emailing a death threat to Louise Mensch, the Conservative former MP; he had also harassed her on Twitter. In other extreme cases, the police and Twitter Inc have acted.
But recently the problem has become more pervasive. Caroline Criado-Perez is a journalist who campaigned for women's faces on banknotes to succeed Elizabeth Fry, the social reformer who is to be replaced by Winston Churchill on the £5 note. Last week her campaign secured its goal, as Mark Carney, the new Governor of the Bank of England, announced that Jane Austen would feature on the next £10 note. Ms Criado-Perez's triumph was ruined, however, by a wave of abusive messages she received on Twitter, including threats of violence and rape.
Anyone who has enjoyed success, or any small degree of fame, might be familiar with the envy and resentment that come with it. Such sentiments are unpleasant and reflect poorly on human nature, and in earlier times – that is, before 2009 – they would have largely failed to find expression. But Twitter, as well as democratising news and silly jokes, has made it easier to express impulses that ought to stay unexpressed.
Some people, mostly men, will say that this is the rough end of the tumble of free speech and, anyway, you can just block them. But there is a difference between verbal abuse and threats of violence, and a difference again between foolish outbursts in the heat of argument and sustained threats against women because they are women.
This is something to which neither the police nor Twitter, now that it is a large company responsible for a ubiquitous service, has yet adjusted. Mark Luckie, Twitter's manager of journalism and news, responded badly to demands for Twitter to do more about users who threaten violence by locking his Twitter account yesterday. The company should respond more constructively to the petition launched this weekend for it to put a "report abuse" button on every user's page.
This is a sensible suggestion: the website's current system for reporting violent threats is hard to find and to use. But the company ought to be doing more to help the police to trace and deter persistent offenders. Many of the Prime Minister's arguments about Google's responsibility to use its staff's computer skills to help deal with the problem of child sex abuse images also apply to Twitter and threats of violence. Google and Twitter have not caused these problems, but they have facilitated them, and they are therefore under an obligation.
Threatening behaviour on the internet is no different in principle from physical stalking, and Twitter and the police should take it just as seriously.