The huge expansion of online social networking sites has opened up an etiquette minefield, complete with snubs, awkward faux pas and ample opportunity to give and take offence.

With networking websites such as Facebook and MySpace expanding expedientially, the rise of cyber friendships has brought with it a new set of social niceties, conventions and potential embarrassments.

Such sites are designed to set up an online network of friends to keep in touch and to exchange gossip but, as in all social situations, the results can be fraught. How can you separate friends from mere online acquaintances? How do you tell someone that you don’t want to be their friend? What do you do when you discover that you suddenly have countless “friends” whom you either don’t know or don’t like?

Stephen Fry, whose portrayal of P.G. Wodehouse’s Jeeves gave the impression that he could extricate himself from any social situation, discovered the social pitfalls this week when he was forced to hide his Facebook profile from would-be friends.

As everyone who joins the networking website eventually discovers, the problem is not having too few people wanting to call themselves your friend but too many. Within a week of joining, Fry began to receive 150 requests a day from admirers hoping to be accepted as friends – a status that would allow them to view his full profile and receive updates on his life. “I only joined last week,” an exasperated Fry told The Times. “I closed down my pages to new friends and visitors [this week], so I managed five days of hectic, exponential build-up before I saw that it was pointless to continue.”

Fry was caught in a classic Facebook double bind – he did not want to offend people by rejecting their requests but knew that accepting all invitations would render his membership useless. Facebook works by giving users updates on their friends’ activities. If that list of friends expands by 20 an hour, interesting updates will be lost in an ocean of small-talk.

The actor attempted to avert social meltdown by creating “Stephen Fry’s Friendship Proxy Group”, open to all-comers. “If you join this group instead of applying for friendship, you might save me a fair amount of heartache in having to turn you down on account of there not being enough hours in the day,” he wrote. “Some of you are friends, of course, and some of you technically aren’t, but you’re all very welcome to this group, which I hope you’ll enjoy. Consider membership to be congruent to friendship.” Currently it has 2,500 members.

The plan was moderately successful until Monday, when the BBC News website published a story confirming that his profile – identifiable from a photograph of the actor with his face reflected in a mirror – was genuine and not a hoax concocted by a fan.

Fry was deluged. “I suppose people might reasonably think me naive, or indeed idiotic, to have imagined that I could inhabit a social networking site peaceably,” he said. “I manage to shop in supermarkets and travel on Tube trains, however, and I had hoped maybe it would be possible to maintain a Facebook presence also. The frustrating thing is that this kind of thing causes others to think that well-known people are stand-offish and don’t deign to participate in the world others daily involve themselves in. Heigh-ho.”

Fry’s experience is extreme because of his celebrity but a similar social labyrinth awaits other Facebook members. At the heart of the problem is the word “friend”. When people first set up Facebook accounts they search for their genuine friends and ask them to be part of their network. It is only days or weeks later that real friendship and Facebook friendship begin to diverge. Each successive request from odious former colleagues and erstwhile girlfriends stretches the definition of friend to breaking point.

The site’s designers have done their best to overcome the crushing awkwardness of friendship selection – including the option of allowing people to see a restricted version of one’s profile – but there is no escaping that anything other than full acceptance will be seen as a snub.

Facebook is vulnerable to gaffes in a way that its competitors MySpace and Bebo are not because it has attracted an older, more class-conscious audience. It was invented in 2004 for undergraduates at Harvard University and its British audience also spread from the campus.

Two thirds of its 3.2 million British users are aged between 18 and 34. The same age bracket represents less than half of the 6.5 million members of MySpace – owned by News Corporation, parent company of The Times – and a third of Bebo’s 4 million users.

Facebook’s members are more likely to be richer, better educated and have more prestigious jobs, according to Nielsen NetRatings. Half of Facebook’s British members are university-educated. On MySpace it is a third and on Bebo it is a quarter. Facebook has a higher share of students, professionals, executives and teachers, and the highest proportion of households with a shared income of more than £50,000. So Facebook members are much more likely to be prickly, middle-class adults fearful of becoming social pariahs.

Sonia Livingstone, Professor of Social Psychology at the London School of Economics, said that snubbing people on Facebook differs from real-world snubs because it takes place in a sharply defined moment. “We’re used to snubbing people. We don’t call them back. We don’t answer their holiday postcards. We say we’ll meet up with them for a drink when we have no intention of doing so. But here there is a very evident decision moment.”

Rejecting friendship applications is more stark than offline friendship because decisions are made without explanation, Professor Livingstone said. “You cannot say, ‘I would love to have a drink with you but you cannot see my holiday snaps’.” If the new social awkwardness created by Facebook is turning people off the idea of social networking, it is not reflected in the amount of time people spend on the website. Facebook’s members dedicate an average of 143 minutes a month to the site – more than MySpace’s users but less than Bebo’s.

Professor Livingstone’s research into the social networking habits of 13 to 16-year-olds suggests that Facebook has a reputation as the place to join when Bebo and MySpace users have grown up, but this perception may be short-lived. Research published last month by Parks Associates declared that users are “chronically unfaithful”. Some 444,000 Britons are members of all three sites, according to Nielsen. Friendster, once a hot social network with 20 million users, is now used by fewer than a million.

Even Stephen Fry is likely to move on to the next social networking phenomenon when it appears. “I find myself constitutionally unable to coexist with new technology without wishing to penetrate its mysteries and implications. The same thing happened to me with Prestel and Compuserve, long before the internet had left the confines of government and academia; even back then I was in the public eye enough to build up an unsustainably bulky correspondence.”

A guide to internet manners

1 Facebook is merely the latest technique for socialising. The manners of doing so are no different from traditional ways of making friends in the agora, at the parish pump, the launderette or the pub. Let us not fall into the folly of neophobia. Lord Redesdale lost his temper if anybody had the cheek to ring him on the newfangled device of the telephone during dinner.

2 This is a more generous, inclusive age. We want lots of friends. Polonius seems an old bore when he recommends being familiar but not vulgar. “Do not dull thy palm with entertainment of each new-hatched chum on the internet.” But the old bore has a point.

3 Friends come, like everything else these days, in league tables. We want some to know that we are off on an enviable cruise. But only other, closer, friends need to know that we have a new lover. Facebook is a medium for the young who have not learnt to be discriminating in their friendships. Their enthusiasm is touching, but tiresome, and potentially dangerous.

4 In entering our daily doings on Facebook, a decent restraint is polite. Do not imitate the writers of annual “round robin” letters to their “friends”, by assuming that a clunking catalogue of our petty triumphs and those of our children and pets are as fascinating to others as they are to us.

5 We hate to hurt others. So how do you tell somebody that you do not want to be their friend? Tricky. The techno-Einsteins have devices for withholding friendship surreptitiously. But, friends being what they are, you will be found out.

6 Truth makes the best manners. We do not need to be absolutely honest, which can cause maelstrom. But Facebook should introduce a key reply that says words to the effect, “I am full up. No room for any more friends”. This goes against the inclusive spirit of our age. True Victorians, who objected to being called by their first names, would have a Savit reply saying: “Certainly NOT.”

7 You really do not need a host of “friends”. This is not a contest in who is the most popular boy/girl in the class. If you can find a few real friends in our brief cruise of this Ship of Fools, you are winning. “Grapple them to thy soul with hoops of steel.” And, in spite of the wonders of the internet, the old face-to-face method wins.

8 The golden rule for Facebook Etiquette is the same as for manners generally. Manners mean how we behave in society. Treat others as you would like to be treated yourself. And this does not mean having to admit every unknown Tom, Dick and Harriet to your friendship.

Philip Howard