When, in 2008, Britain's Mail on Sunday identified who it thought was the anonymous stencil artist Banksy, there were numerous complaints. "Why have you done this? I don't understand," wrote one disgruntled reader. "You have ruined something special."
As Robin Barton, owner of Bankrobber Gallery which sells Banksy prints, said, "People really don't want to know who Banksy is. Even collectors don't want to me to tell them who he is. It's weird but that's what keeps it fresh for me ... it's more fun and much more profitable not knowing."
Barton is right on all counts; anonymity, fun and profit are among the hallmarks of the Bristol-born street artist's internationally acclaimed career. To write this widely sweeping biography, an account of Banksy's career and market trajectory - as well as forays into the turf wars of graffiti artists, the contempt Banksy is held in by some and the acclaim from others - journalist Ellsworth-Jones made it clear to those he spoke with, Banksy's PR people and friends among them, that he had no interest in revealing the artist's identity.
There has been a remarkable cone of protective silence over Banksy's identity even though he has worked in loose collectives and often moved about in public. In an age when there is a relentless pursuit of the most mundane claim to celebrity status, his uniqueness is even more alluring, especially when his art and life is so public.
Ellsworth-Jones traces the artist's origins from Bristol where the middle-class Banksy was part of a group of graffiti artists working in a tough part of town. Today it is a strange world he occupies, his work bought for astronomical sums, his street art protected by councils and, most interestingly, Banksy's seeming indifference to the whole thing other than to be allowed to continue working and maintaining his anonymity.
He sanctions some prints and has lately taking to signing them to stave off frauds, rarely authenticates his street art (although he identifies fakes) and seems indifferent to amassing wealth. "The money my work fetches these days makes me uncomfortable," he told the New Yorker. "But that's an easy problem to solve - you just stop whingeing and give it all away. I don't think it's possible to make art about world poverty and trouser all the cash."
Banksy has been a lifeline for galleries such as the Bristol City Museum he held in such affection that he put on a typically witty installation show there in 2009. The gallery drew almost five times as many visitors as the previous July - 4000 a day - and the exhibition was the second most visited in Britain that year.
In this highly readable book, Ellsworth-Jones tells of other exhibitions where the queues were hours long and how Banksy's work came to be as common in Sotheby's as a wall in East London. But within the graffiti world - those guerilla attacks by old-school writers - Banksy's stencil style is held in contempt and he has admitted he wasn't good at freehand graffiti: "Too slow."
Stencils are too easy, too glib, his streetcorner critics say, and Banksy art has been anointed and protected by the art world and civic authorities. But they are in a minority. Banksy's business may be big business but it seems others have cashed in more than he has. Not that he - the anonymous outsider and widely acknowledged polite, smart and funny "good geezer" - seems to care. "I love the way capitalism finds a place," he has said. "Even for its enemies."