Last weekend I had the misfortune to stumble inadvertently into what should have been a very private situation. While attending a barbecue on a sunny day in Cardiff, a major row erupted between a mother, Zoe*, and her teenage daughter, Claire*.

It started innocently enough before developing into a full blown and major row that cast a gloom across the event. The issue seemed so significant it has caused me to do a lot of thinking since.

Zoe was first knocked out of her stride when a friend asked her if she should be drinking. “What do you mean?” she asked. “It’s only a glass of wine.”

“But,” came the reply, “my daughter tells me that you’re an alcoholic.”

“What!” exclaimed Zoe.

“Yes, it says so on your daughter’s social-networking site.”

With that, Zoe rushed to confront Claire with the accusation. Claire retorted by stating that her mother must be “stalking” her on the site. And things went downhill from here with both Zoe and Claire leaving the event, although not before verbally abusing one another further in full view of everyone present.

Afterwards it was discovered that Claire is one of 220 girls from the same school who all share a social-networking site. Although Claire has only three close friends, all the girls’ messages on the site are read by everybody. Claire had posted a message stating that she was concerned about her mother’s drinking and believed she had turned into an alcoholic. Clearly, some of the other site members must have been concerned and told their parents. While Zoe might argue that her drinking was only social and kept within normal bounds, Claire clearly thought otherwise.

Zoe’s case illustrates the strengths and dangers of social-networking sites and the complex moral and ethical issues surrounding their usage. A recent survey found that British teenagers are spending an increasing amount of time on sites like Facebook and MySpace; 22 per cent of those surveyed visited them more than 10 times a day, with girls especially enthusiastic.

But many teenagers view these sites as fun and seem unaware of the long-term personal havoc they can create with a click of a button. The same survey found that parents generally have little idea of what their children are up to when using the sites. More than one out of 10 teenagers had posted potentially damaging pictures of themselves, thereby creating a “digital tattoo” that could haunt them for the rest of their lives. Today, if you wish to find out something about your new school friend, you simply access the internet. Within moments you may find out more about your friend than through nine months’ conversation.

Teenagers and younger children are often not very adept at self-censorship. They may inadvertently “bully” classmates when, fundamentally, they had no intention of doing so. They often send out messages, as Claire did, to everyone, when in the past they might have kept these as a secret between a few friends. On social-networking sites, teenagers expose their views on anything and everything: school, teachers, sex and much more. They also live with the consequences of their actions, both in the short and long term.

Research into the use of these sites is beginning apace, focusing upon the moral, legal and ethical issues, the psychological implications, the mental-health issues, internet safety and identity theft. But they pose real problems for teachers, not least when deciding if an issue is an ‘in-school’ or ‘out of school’ matter? New technology and fast-developing, multi-choice sites have blurred the distinction, just as mobile-phone usage and text messaging has led to an increase in bullying within and outside the school gates.

The time has come for educational policy makers to start to think seriously about the implications of social networking, not only for child-protection issues but for the future well-being of the teaching profession and for future generations of young citizens. While no one wishes to see further censorship imposed, there is a need to educate children and young people about the risks and advantages of using the internet and, in particular, social-networking sites.

It is crucial that both teachers and administrators start by learning about the array of available social networks for children and young people to use. Teachers can turn these sites to their own advantage by using blogging software to set homework and by allowing pupils to publish their assignments for others to comment upon and so create learning resources.

Specifically, schools need to educate pupils about the appropriate risks of using both social-networking sites and the internet, not only for issues of personal safety and privacy but also for reasons connected with good citizenship, plagiarism, the reliability of information and inappropriate behaviour.

These debates need to involve parents, a review of school policies and, in certain cases, the police and possibly social services. Only then will we be able to prevent scenes like the one between Zoe and Claire from happening again.

* Names have been changed

Professor Ken Reid, Deputy vice-chancellor of Swansea Metropolitan University and chair of the National Behaviour Attendance Review in Wales.