Further evidence that Finland’s schools are not all havens has emerged. A teachers’ union here found that more than one in ten teachers has experienced internet bullying.

Thirteen per cent of the 400 teachers questioned by the OAJ union said they had experienced online harassment. The problem was particularly acute among females under 40 teaching pupils aged between 13 and 16. In most cases the trouble was instigated by pupils, but in a third of cases it was at the hands of parents. The bullying involved messages being sent directly to the teacher’s mobile phone or email account, as well as abuse posted online.

Teachers said the harassment included offensive remarks about their teaching abilities, what they looked like or various insulting, threatening or sexist remarks. In some cases, there were even online calls for them to be killed.

Vesa Ilves, who conducted the research, said: “Two teenage boys threw stones at a teacher’s car. The teacher reported it to the police, so one of the boys opened a Facebook page where he mocked the teacher and teacher’s family.”

Other cases have included two pupils producing an online “test” about a particular teacher. “In the local police’s opinion, the test answer options were slander,” Mr Ilves said.

Nina Lahtinen, an OAJ lawyer, emphasised that the age of criminal responsibility in Finland is 15. “Normally, if the pupil says something bad about the teacher, then the teacher is told, `they are young - you have to just take it,’” she said. “But if the teacher says something bad about the pupil, that is more likely to go to court.”

In fact, this occurred in May 2010, when a female teacher in Oulu, northern Finland, was fined for calling a 17-year-old boy various obscene things.

“If, for example, a pupil was insulting a teacher’s appearance or personality, the teacher would probably lose the case unless she could prove that the remarks seriously harmed her reputation,” Ms Lahtinen said. “Even the Facebook pages focused on abusing a particular teacher did not cross this line.”

In May 2007, the union dealt with a case that did cross the line. A boy of 15, from Nurmes, in eastern Finland, was fined in a test case. He filmed a video of a female teacher singing karaoke at a school party and posted it on YouTube. He named the teacher and described her as a “lunatic singing the karaoke of the mental hospital”. The video quickly went viral. The court said the boy had “falsified facts” about the teacher’s mental state and caused her to suffer depression and insomnia.

Teachers in Finland can also face other kinds of malicious allegations, but they have one advantage over their UK counterparts: the papers here do not publish the names of people involved in trials until they are found guilty - and only then, by convention, for serious crimes.

But for Ms Lahtinen, this makes little difference: “Even if they don’t publish the teacher’s name, they might publish the name of the school or if they teach French or English, so people know who it is.”

• Original print headline: View from here - Cyber-bully pupils beat the rap