But newspapers have an unwritten compact that they never, under any circumstances, expose each other — one reason why Robert Maxwell and Conrad Black remained in business for so long. Over the last few decades only Private Eye (which is serialising this book — presumably no paper would do so) has made it its business to draw attention to press corruption and hypocrisy.

This code of omerta is very widespread. Davies shows that no paper will ever expose the illegal practices of rivals because they are all at it. For example, newspapers are able to obtain, within minutes, possession of a wealth of personal data about British citizens — credit-card statements, bank statements, driving licence details, ex-directory phone numbers, itemised telephone billing etc. Davies shows that it is not just tabloids that do this. So-called broadsheets are also guilty.

All this information is obtained through bribery, trickery and deception. As a whole, newspapers are careful not to carry out this furtive work themselves. It is sub-contracted to third parties. Davies claims, for example, that the Sunday Times at one stage hired a reporter on the explicit basis he was not on the paper’s books. ‘The object was for him to handle the dark arts,’ asserts Davies, ‘and just in case he got caught doing something illegal, they could deny their connection to him’.

The drive to acquire intimate details concerning British citizens has given rise to a cottage industry based around the illegal acquisition of personal information. It is inhabited by bent policemen, phone- tappers, private investigators, professional conmen, civil servants on the take, Benji the Binman (who famously made a living sifting through celebrity dustbins) and so forth.

Nick Davies expertly guides the reader through this horrible, scary, illicit world. I had never before realised what a high proportion of newspaper ‘scoops’ — from the Sunday Mirror exposure of David Mellor’s affair with Antonia de Sancha to the majority of royal stories — rely, innocently or otherwise, on criminal conduct somewhere along the chain.

Occasionally these practices come to light. For example, in 2006 a private investigator, caught blagging information out of British Telecom, was charged and convicted. With the exception of a small story on the Guardian website, no newspaper reported this event, let alone exposed the sordid underworld that lay behind it.

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