'Friends don’t spy,' wrote Stephen King, 'true friendship is about privacy, too.'

According to news reports yesterday, pupils at a leading independent British prep school are being finger-printed as part of a new payment system for the school dining room. This has reportedly happened without the specific consent of parents.

Haberdashers' Aske's Boys' school took its pupils out of lessons to have their thumbprints recorded. In future, students will press their thumbs against an electronic scanner each time they buy lunch or a snack. The price will be charged to their account.

Parents, who reportedly pay annual fees of more than £15,000 per child, have complained that they knew nothing about the procedure. The school simply posted a notice on its website, which many parents did not see.

Indeed, most students knew nothing about the school's plan until it was carried out.

The school claims that many other schools have already taken the biometric route when it comes to student data.

The issue of parental consent is, of course, a hugely important one. Parents should bear the ultimate responsibility for deciding on appropriate levels of privacy for their children. How else are they to be held responsible if their children fail to respect the privacy of others?

Parents must be given the authority to match that responsibility.

For their part, governments should provide penalties for privacy incursions that are generally adjudged to be inappropriate. However, the state should never seek to rob parents of their rightful role as primary guardians - and even less so should schools.

In the case of schools fingerprinting or using other biometric data, however, there is another issue of equal concern. By extracting biometric information from its young charges, the school is encouraging them to believe that surrendering such information is a normal part of life.

Studies suggest that, when it comes to privacy invasion among young people, we already have cause for concern.

This is especially true in the age of 3G and 4G mobile internet technology, broadly uncensorable video and social networking sites and the increasing use of data-mining by marketers and other sectors of business.

Twenty-five percent of British young people, aged 16-25, say that they are 'addicted' to their mobile phones. They also admit to feeling 'separation anxiety' when their phones are removed.

For the young, this dependency on phones - particularly smart phones - means that the online experience plays an important role in establishing personal identity.

Mark Zuckerberg, the billionaire founder of Facebook, famously said, 'Privacy is dead - get over it.' His statement sounds shocking to many, yet it reflects the mindset of many of his peers and, perhaps more so, the next generation.

The younger end of the Millennial generation and the generation following them (Gen Z?) both appear more relaxed than older cohorts when it comes to yielding personal information online. In the process, they often overlook the fact that strangers can access this information.

They also forget that what goes digital usually stays digital - either because we simply forget to remove it or, more often, because you can't completely expunge a digital echo.

Many people, including the not-so-young, frequently upload personal data which they might later find embarrassing - or even damaging to their job prospects. In doing so, they also unwittingly open themselves to very personalised and intrusive online advertising.

When it comes to the young, this taste for risk may seem predictable, given their natural urge to explore lifestyle options and to develop identity beyond a role in the immediate family.

The internet promises attractive opportunities for mass collaboration and a buy-in to tribes beyond the front door.

Though it carries benefits, digital identity also carries a sometimes heavy price tag.

For example, cyber-bullying is a growing problem in this country, as is the ease of access to pornography among children.

In the UK, says the NSPCC, 38 percent of young people have been affected by cyber-bullying and 28 percent do not report the abuse, which often comes via emails and text messages.

According to Childline, its web and phone-based counselling service, cyber-bullying is particularly insidious because it circumvents the normal protections children might expect when they come home and close the front door. In the age of fully wired homes and 3G and 4G mobile technologies, cyber-bullies can seem ubiquitous.

Cyber-bullying can also involve more than one perpetrator, taking on a viral impact, as young copy-cats - who may not even know the victim - jump on the bandwagon. To make matters worse, cyber-bullies often hide their identities behind fake social networking avatars.

This is a growing problem in much of the developed world. According to a 2012 report by the US Department of Health and Human Services, 52 percent of American students have been cyber-bullied. Meanwhile, 25 percent of teens have been bullied repeatedly through their mobile phones or the internet.

The Nine television network in Australia announced in 2009 that 25 percent of the nation's children had experienced cyber-bullying. Meanwhile, 22 percent of parents of children aged 4-18 admitted that they had no control over their children's online activities.

Only one third of parents had internet monitoring in place.

Access to online pornography is another cause for heartache among children and parents.

Last week, a major UK newspaper featured a mother's heart-rending response, after her 11-year-old son had been subjected to pornographic videos online. He had viewed the videos, some of which featured violence, because his friends had pressured him to watch.

As a result of just one viewing, he has become withdrawn and now has trouble sleeping. Normally a well-adjusted boy, he is unable to reconcile what he has seen with the type of respectful behaviour he's been taught to value in others. He wishes, says his mother, that he could 'unsee' the videos.

Bullying and pornography represent strong threats to the mental health and emotional development of young people.

Fingerprinting children in school certainly cannot be categorised alongside these social ills. Yet encouraging a low respect for personal privacy among young people is in itself, if not dangerous, at least troublesome.

In our hyper-connected age, privacy is increasingly falling victim to an over-engagement with cyberspace. This is, for many people, a cause for anxiety.

Next month, the America Psychiatric Association will, for the first time, include Internet Addiction Disorder among its plethora of recognised conditions.

Meanwhile, psychologists already recognise Communication Addiction Disorder - a mental condition in which people feel compelled to be in constant contact with others, usually online, even when there is no practical reason for being so.

A global conference of psychiatrists meeting in Sydney a few years ago, announced ours to be the Age of Paranoia. Obviously, there will be many factors contributing to this, but our digital hyper-connectedness must surely be one.

When it comes to the internet, anxiety springs in part from a fear of being unable to switch off and, in some cases, a fear of missing something if we do. The latter is so prevalent among the young that MTV coined an acronym for it - FOMO, the Fear of Mission Out.

Sixty percent of Australian CEOs say they feel anxious because they cannot disconnect from work - they feel too coupled with their smart phones. Meanwhile, an estimated 40 percent of children in the UK who have a phone are sleep deprived.

If, as these and other statistics seem to suggest, overuse of the internet weakens our mental and emotional defences, we need to be very awake to the possibilities of revealing too much online.

The fact that paedophiles and child-pornographers use social networking sites to trawl for potential victims is already well known. They prey upon young people who have not yet learned that naiveté is unhelpful online or that privacy is a currency which must be dispensed very sparingly.

As human beings, our respect for privacy is in many ways a reflection of the esteem in which we hold our own individuality. The exceptionality of a human fingerprint or iris print represents a powerful symbol of the uniqueness of the person to whom they belong.

This is why fingerprinting has normally been associated with police work and crime.

Law breakers are deemed by society to have surrendered at least some of their natural right to privacy.

In taking the fingerprints of a criminal suspect, society is in effect declaring that, if found guilty, he or she will surrender not only their physical freedom but their right to future anonymity within the system.

Over the years, fierce battles have been fought within civil the liberties arena to keep fingerprints from being misused, or taken unnecessarily. How can a school possibly guarantee the safety of its electronic records, when even national governments and multi-national banks have 'lost' sensitive digital information to thieves (or, in some cases, the garbage collector)?

Some might argue that the rise in use of CCTV cameras and the increasing use of mobile phones for data-mining purposes are already redefining personal privacy.

This simply serves to make my point. We should guard jealously what privacy is left us - and encourage the young to do likewise.

Fingerprinting and the use of biometrics generally in schools should be abandoned. There are other options for streamlining their processes. Swipe or RFID cards would be cheaper and represent far less of a threat to young minds and their attitudes to privacy.

True friends of children will recognise that Stephen King is right and behave accordingly.