The internet's great advantages – speed, access and shared communication – can also have drawbacks, as Richard Dawkins found out last week. Here, author James Harkin reflects on the nature of discourse when everyone has their say

Even hell hath no fury like an electronic crowd, as Richard Dawkins discovered to his cost last week. Dawkins's mistake was to update his website with a letter politely giving notice of a few planned changes to its "community" bulletin-board, where 85,000 enthusiastic atheists come to air their views and discuss them with like minds.

"Dear forum members," his cheery email began, and before long the feedback was coming in thick and fast. Dawkins returned to his computer to find himself being described as "a suppurating rat's rectum". Another anonymous community member expressed a "sudden urge to ram a fistful of nails down your throat", while a third described the author of The God Delusion as having "a slack-jawed turd-in-the-mouth mug if ever I saw one".

The reaction must have confirmed Dawkins's worst suspicions. He was already concerned at the amount of gossip, abuse and irrelevant discussion turning up on his site, which was why he was keen to subject it to greater editorial control. Dawkins is no wallflower, but even for someone familiar with the fury of American creationists, the bile he unleashed seems to have taken him aback.

"Surely there has to be something wrong with people who can resort to such over-the-top language, overreacting so spectacularly to something so trivial," he wrote. "Was there ever such conservatism, such reactionary aversion to change, such vicious language in defence of a comfortable status quo? What is the underlying agenda of these people?" There must, he felt, be "something rotten in the internet culture that can vent it".

His language is extravagant, but he makes an interesting point. When anyone can have their say, what use is the stuff that comes out the other end? What can be done with it, and who is going to be in charge of quality control when things go wrong?

This weekend, three Google executives will be mulling over at least some of those questions. Last Wednesday they were convicted and awarded six-month suspended sentences for allowing a clip of an autistic boy being viciously bullied to play on Google Video. Google, the judges claimed, violated the boy's privacy, even though the company removed the video as soon as it was brought to its attention. The judgment is likely to be overturned on appeal; were it to stand, it would make much of the worldwide web unworkable.

Once again, however, it raises the question of what to do with the mass of material that is piling up on social media sites such as YouTube, Twitter, Facebook and Google Video. For the internet gurus who travel around like fire-breathing evangelists, preaching hate for the old world and an all-consuming love for the new, the answer is clear. The vast ocean of electronic information out there on the net, according to them, represents a historic triumph of web users over the institutions that have kept them at bay.

There's no question that the deluge of data can be a great resource, or that social media is a fantastic way of passing around nuggets of information. Much of our media diet is made up of recommendations from social media – shared playlists on Spotify, for example, or articles that come our way via Twitter. It's also a great way to get things out, burrowing under the control of authorities. Trafigura is a case in point; in October 2009, a single elliptical tweet from the Guardian's editor lit the touch paper of a campaign that helped overturn a bullying legalistic attempt to silence the paper's investigations into the company.

Sometimes, however, the bullies are on the other side – witness the over-the-top online monstering of Daily Mail columnist Jan Moir in the same month, after her ill-advised ruminations on the death of singer Stephen Gately.Both examples, however, can be seen as two sides of the same coin. The paradox of the "wisdom of online crowds" is that it only works in clubbable, relatively small groups of like-thinking minds. The reason why the richest and most productive audiences online are for the most arcane subjects – on the relationship between economics and law, for example, or how to care for cats – is because everyone involved feels part of an exclusive club dedicated to finding out more about the same thing.

However, it's for exactly the same reason that many of these clubs can become breeding grounds for vicious tribalism. The brevity required for communication on Twitter does not lend itself to decorous etiquette, but neither is it the soul of wit to circulate snide, snarky tweets to an enthusiastic group of followers.

Too often the online audience separates into a series of rival gangs, each of them patting each other on the back and throwing stink-bombs at the other side. In this environment civility can disappear, with the result that those who do not take an extreme approach in offering their views decide that online forums are not for them.

When everyone is reinforcing everyone else's opinion in an online echo-chamber, there's little need to state a case or debate one's opponent. It's easier – like the schoolyard bully – just to abuse them. The other problem with online "communities" is that decisions about quality often become snagged in a highly conservative and self-reinforcing feedback loop in which everyone queues up to follow the leader.

In an intriguing experiment, three social network theorists at Columbia University used the web to invite more than 14,000 young people to rate songs by relatively unknown bands and download the ones they liked. The researchers began by dividing their subjects into two groups. The first group was asked to make their decisions independently of each other, while the second was allowed to see a rolling chart of how many times, in descending order, each song had been downloaded by others – telling them, in effect, which songs were the most popular among their peers.

When they came in, the results were as clear as day. Those who could see the download charts, the researchers discovered, tended to give higher ratings to the songs at the top of the chart and were more likely to download those songs. People tended to like songs more, in other words, if other people liked them. The result was to make the choices of those in the second group highly unpredictable, with a great deal depending on who rolled up to make their choices first. Identical songs were judged to be hits or flops depending on whether other people had been seen to download them earlier.

In their haste to rustle up an audience, mainstream institutions have not quite grasped the implications of all this, which is why they keep trying to flatter the vast, anonymous masses by inviting them in. The results can be ruinous.

When Penguin invited millions of web users to collaborate on a "group novel" called A Million Penguins in 2007, for example, the story was so chaotic as to be unreadable, and kept splintering off in new directions; at one point it even divided itself into "Novel A" and "Novel B" with links to alternative endings. Characters multiplied out of control, paragraphs and whole sections ended at random, plot lines drifted hopelessly and were left hanging in mid-air. Some collaborative novelists took it upon themselves to try to sabotage the whole experiment; one took the trouble to litter the text with references to bananas.

In the end, just like Dawkins, the organisers were forced to "lock down" the project for a few hours every day to ward off the vandals and to allow the novel time to develop. One of the reasons for the novel's incoherence, it became apparent, was that not even the masses of novelists who had queued up to help to write the book had bothered to read what had gone before. They were too busy writing.

Penguin's failed attempt to persuade an electronic crowd to co-write a novel illustrates one last problem throwing open one's organisation to electronic feedback. Often it only works until its beneficiaries realise that, no matter how many messages they fire off, those in authority are bound to retain the ultimate reins of control.

At that point it is likely that they will switch from offering "good" or helpful feedback into pushing "bad" or destructive feedback back into the system. The angry, splenetic or downright abusive tone sometimes exhibited by those former fans of Richard Dawkins is a good example of this kind of feedback. By then, of course, it's a little too late to show them the door.

James Harkin is the author of Cyburbia: the Dangerous Idea That's Changing How We Live and Who We Are. Published in paperback in April.