The “abolition of privacy” was the stated intention of the horrible Marxist sociology professor Howard Kirk in The History Man, Malcolm Bradbury's novel of the early 1970s. The private is necessarily inseparable from the public, he gleefully pronounced - and privacy is, in any case, a redundant bourgeois notion. Bradbury was a fine and prescient writer, but even he cannot have anticipated the extent to which his protagonist's thesis would become more or less true, and with our gentle and sometimes unwitting connivance.

As this book (by two rather more agreeable academics, übernerds from Southampton University) explains, the boundary between what is public and what is private has become blurred, transformed forever by the computer revolution that has carried us all along in its wake, without us ever getting to grips with the implications of the new technology. We can be snooped upon, 24 hours a day, through the medium of those various ingenious devices that we have acquired to make our lives ever-more comfortable. Just beyond the edge of our eyesight lurk sophisticated fraudsters, the police, the security services.

Early on, Kieron O'Hara and Nigel Shadbolt explain the way in which our privacy has been gradually, almost imperceptibly chipped away and reveal our cheerful collusion with the process. “If the short-term benefits of technology are good enough, we tend not to question them,” they write. “Had the government demanded that we all carry around electronic devices that broadcast our whereabouts to a central database, that the information should be stored there indefinitely and that the police should be able to access it with relatively minimal oversight, there would have been an outcry.” But of course we carry around mobile phones voluntarily. As the authors balefully put it: “The benefits, we generally reckon, outweigh the costs - which they probably do, but that is merely luck.”

But it is, of course, that sinister winking and bleeping basilisk in your study, or your child's bedroom - the personal computer - that provides the conduit by which your privacy (and by extension, your bank account) can be readily compromised. The authors take us through new and improved encryption systems in a chapter that left me numb with terror, boredom or incomprehension. Later, the various risks are evaluated - the “mashup”, for example, which in the sort of language used by normal human beings is nothing more scary than cross-referencing. By bringing together data from different sources, a result of the new “Web 2.0”, you arrive at an infinite number of applications that can be either benign or otherwise. Cross-referencing data about convicted sex offenders with the growing number of highly detailed geographical mapping systems enables one to identify a wrong 'un and then go straight round to his house to set him on fire, for example. As the authors say: “Such sites do not create any extra information...all the information is in the public domain already ... but when it is kept at different locations, on paper, or even in different databases which are relatively hard to search, the effort involved in producing a photograph of your local sex offender would be too high for all but extremely concerned individuals to undertake. Thanks to mashups, this practical obscurity no longer obtains.”

There are bleak warnings, too,about “pervasive computing”, the tendency for an increasing proportion of our household accoutrements to have some sort of limited inbuilt computer which, though of minimal intelligence individually, nonetheless contributes to the store of personal knowledge available to those who might want it. Smart training shoes, for example, which tell you how grotesquely fat you are and how far you ought to run to shed those extra pounds.

There are some kind words for luddites such as myself. Even the privacy and security of computer illiterates deserves to be respected, regardless of their fecklessness or ignorance, argue the authors. But still, in the end, they reject too much intrusive and authoritarian state regulation of the internet, insisting instead that the public must become more aware. Nor is retreating into a technology-free ghetto much use: “It is virtually impossible to go through life in a western democracy without leaving an information trail behind and as this is now the case, more good will be done by ensuring that people are aware of that brute fact, rather than by expensively engineering the state's institutions to allow some people to opt out.”

Shadbolt and O Hara have kick-started a new debate about what we mean by privacy. From somewhere up above I can hear Howard Kirk chuckling to himself.

The Spy in the Coffee Machine: (The End of Privacy as We Know It) by Kieron O'Hara and Nigel Shadbolt
One World £9.99 pp294

Times Recommends

• The 100 Best Books of the Decade
• The Times picks the 50 best paperbacks of 2009
• The conversation: James Ellroy