These and a dozen other observations led Lanier to conclude that something had gone terribly wrong: that we had reached a point where the network was being exalted as far more important than any individual. It is a thesis he explores in his book . "The central mistake of recent digital culture is to chop up a network of individuals so finely that you end up with a mush," he writes. "You then start to care about the abstraction of the network more than the real people who are networked, even though the network by itself is meaningless. Only the people were ever meaningful." One of the articles of faith of the "open culture" movement is expressed in the aphorism, "Information wants to be free". Typically it is used as a justification for illegal file-sharing but, as Lanier points out, information can't in any real sense "want" to be free. "Information of the kind that purportedly wants to be free is nothing but a shadow of our own minds and wants nothing on its own," he writes. "It will not suffer if it does not get what it wants." Information only becomes real when it is experienced by a real, live human being.

Likewise, it takes a human mind to design and build the machines. He uses the example of the series of chess games staged in 1997 between world champion Gary Kasparov and the IBM supercomputer, Deep Blue. Kasparov famously lost the encounter, provoking much hand-wringing about whether computers had finally caught up with humans and were about to overtake us in terms of intelligence. But this was, says Lanier, a massive over-reaction and symptomatic of the pedestal on which we tend to place computers and artificial intelligence. "What happened was primarily that a team of computer scientists built a very fast machine and figured out a better way to represent the problem of how to choose the next move in a chess game," he writes. "People, not machines, performed this accomplishment." If Lanier were just another self-interested commentator railing about the technology dumbing down culture and destroying jobs, then his book would probably be less noteworthy. However, Lanier is no Luddite - in fact he is perhaps the ultimate web insider. As well as a computer scientist he is an artist, multi-instrumentalist musician and composer who pioneered the concept of virtual reality nearly 30 years ago and has had a long and varied career at the cutting edge of computer technology.

So it's all the more remarkable that he is prepared to declare the web has "gone sour" and taken a radical detour away from the early simple idealism that believed technology could empower individuals and inevitably create something good.

This, he writes, has been "superseded by a different faith in the centrality of imaginary entities epitomised by the idea that the internet as a whole is coming alive and turning into a superhuman creature". One of the main targets of Lanier's critique is the concept of the "wisdom of the crowds" or the "hive mind". This is the idea beloved of so many social media enthusiasts that the collective wisdom of a large number of people, generally harnessed online, will exceed that of the individual. Wikipedia is the classic example often cited in support of this theory. Lanier believes that by fetishising and over-stating the power of this collective so-called intelligence we undervalue individual humans. "The 'wisdom of the crowds' effect should be thought of as a tool. The value of a tool is its usefulness in accomplishing a task. The point should never be the glorification of the tool." He considers that "an adventurous individual imagination" is far more valuable than anything produced by a crowd.

Yet we continue to overestimate the potential of computers and the web to behave intelligently, talking down the power of our own brains and consciousness and talking up the abilities of the machines.

"People often make themselves stupid to make the machines seem smart," says Lanier. "We are flooded with information but the only reason we are flooded with information is that the people who designed the software systems don't know the difference between quantity and quality. So if you design something like Twitter where people are encouraged to say, 'Oh, I just had a sandwich', then of course it will be flooded. To design systems like that and then to say, 'Now we have this intelligent software to filter it,' is ridiculous." Lanier is also scathing about the way in which the internet leaves many individuals with little choice but to give away their work for no payment. This effect has been heralded by many (most notably Chris Anderson, editor of magazine, in his book Free: The Future of a Radical Price) as a positive re-casting of our economic system, but it has failed to impress Lanier. In his analysis, this new way of doing "business" takes all value away from the efforts of the individual in order to allow a small number of companies, such as Google, to make money for themselves. "One effect of the so-called free way of thinking is that it could eventually force anyone who wants to survive on the basis of mental activity ... to enter into some sort of legal or political fortress - or become a pet of a wealthy patron - in order to be protected from the rapacious hive mind," writes Lanier. "What free really means is that artists, musicians, writers and filmmakers will have to cloak themselves within stodgy institutions." When was published, Lanier braced for a "faecal storm" - the web faithful don't take kindly to criticism - however, he says he has been pleasantly surprised by the reception the book has received, and the messages of support from many people working inside technology companies.

"I thought I was going to be pounded by people who hated what I had to say. There has been some of that and some ad hominem attacks as one would expect but there has been an extraordinarily warm reception on the whole." And perhaps that's because, unlike other web dissenters such as British journalist Andrew Keen, Lanier's arguments are far more measured than shrill. And, while he raises as many questions as he answers - in places the book reads like a collection of loosely related ideas drawn together rather than a coherent "manifesto" - Lanier's thoughts are a welcome counterbalance to the orthodoxy that the web is an overwhelmingly positive development for humanity.

