Teachers are facing disciplinary action for posting compromising pictures of themselves on social networking websites. The General Teaching Council for England is considering two such cases, but must first decide whether it has jurisdiction to sit in judgment over teachers’ legal, private activities.

Some have been hauled before their heads for bringing their school into disrepute, after posting pictures of themselves on stag or hen nights, according to their unions.

Even teachers without accounts on social networking sites are at risk if they appear in photographs posted by other people.

In many cases pictures are first discovered by pupils on social websites like Facebook, MySpace, Bebo or YouTube.

Andy Peart, deputy head of legal services for the Association of Teachers and Lecturers, said that when heads found such pictures, punishments for teachers could range from a warning to dismissal.

Mr Peart has dealt with several such cases, where teachers did not realise that the comments they made and pictures they posted became, in effect, public documents.

Lewd stag or hen night pictures were typical examples, he said.

“Any photos of such nature which could be deemed risque, and are then viewed by pupils or parents of pupils, could potentially lead to a teacher or member of support staff being accused of unprofessional conduct and bringing the school into disrepute,” he said.

With the internet integral to young people’s lives, he said schools need to educate and protect their staff. He advised teachers to avoid publishing, or allowing to be published, any pictures that could damage their professional reputation.

Some schools have policies banning teachers from being “friends” with pupils on social networking sites. But that is no guarantee that pupils will not see pictures via someone else who is friends with a teacher, or through shared membership of a large network, such as the “London” and “Birmingham” networks on Facebook.

One inner-London primary teacher told The TES that she had been forced to ask for a picture to be taken off Facebook, after being snapped at a party with a young person smoking cannabis in the background. “It’s the habit of young people to take photos and post them on Facebook, and this is done innocently,” she said.

In a Facebook discussion group, a 21-year-old London teacher (photographed holding a sign saying “We love Cock”) said she was alarmed to discover that all her Year 6 pupils had social networking accounts. “I live in fear they will find my account and some not too teacher-like pictures,” she wrote.

Another said: “My Year 11s found me last year on MySpace. That was weird, because it wasn’t in my name and the profile picture was a rubbish sketch of me rather than a picture. They came in and quoted parts of my profile, which I hadn’t made private as I’d wanted to make friends when I was at uni.”