There is no reason this phenomenon won't exist in China. This will add to the existing problems experienced by teachers in crappy schools.

Online social media is being misused to insult, intimidate and smear staff in schools, the conference of the NASUWT teachers' union will hear.

More than one in five teachers had "adverse comments" written about them on websites, according to a survey of 7,500 of the union's members.

A quarter of these insults were from parents - and there were attacks from pupils as young as seven.

More than a quarter included videos or pictures taken without the consent of the teacher.

Teachers had faced racist insults, malicious allegations of hitting pupils, accusations of swearing at pupils and "inappropriate behaviour", says the teachers' union. There had also been threats made against teachers.

"Some have lost their confidence to teach once they see foul and personal remarks made by pupils in their classes and have left the profession.

"Others have been so disturbed by the comments that their health has been affected."