Another lick on the wall: Mark Oliver on graffiti artist Banksy's new book.

A Banksy image on the Israeli security wall. Photograph: PA
Near the start of Wall and Piece, the new book of photographs of the work of London-based graffiti artist Banksy, there is a reproduction of an email which he says his website received.

The message implores the graffiti artist - who tries to keep his real name secret, presumably for fear of prosecution and to increase people's intrigue - to stop leaving his stencil designs around the Hackney area in the east of the capital. The reader is lured into thinking that the complainant is part of the “graffiti is vandalism” mindset, but there is an unexpected twist. The person emailing complains that they can’t afford the spiralling prices in the area due to its perceived coolness. The upset email correspondent tells Banksy:

Your graffiti is undoubtedly part of what makes these wankers think our area is cool. You’re obviously not from round here and after you’ve driven up the house prices you will probably just move on. Do us all a favour and go do your stuff somewhere else like Brixton.

Not many graffiti artists get attacked for driving up property prices, but then Banksy, who is in his 30s and originally from Bristol, is undeniably more of a special case than the kids who just endlessly tag their names.

He is also notorious for sneaking his own works into art galleries in the UK and abroad and fixing them to display walls. And who could forget the fun and games over the kidnapping of his sculpture the Drinker, with Guardian writer Simon Hattenstone embroiled in the ensuing negotiations.

Some of the images in Wall and Piece are unquestionably powerful, such as its front page which shows an anti-globalisation style protester throwing a bouquet of flowers, in lieu of something a tad more dangerous.

Elsewhere, he creates a series of Che Guevara images on a bridge on Portobello Road with the face slowly disintegrating in a critique of the widespread sale of the image on T-shirts and posters at the local market.

A noted Banksy signature device is using part of the environment he is targeting: a smudge on a wall has a urinating soldier created next to it, a car abandoned on a zebra crossing is made to look as if the zebra crossing is going over the roof of the car. A hole in a wall is filled with a graffiti cash machine, spewing out dummy £10 notes bearing the face of Princess Diana.

Arguably his most celebrated pieces are the ones he daubed a few months ago on the Israeli security wall. One photograph shows a young Palestinian looking at Banksy’s image of a window depicting an incongruently peaceful alpine scene.

The Guardian reported at the time that Banksy had recorded on his website that an old Palestinian man said his painting made the wall look beautiful. Banksy thanked him, only to be told: "We don't want it to be beautiful, we hate this wall. Go home."

But to his admirers, what Banksy has to say is important. In a Wikipedia entry on Banksy, the author writes that the graffiti artist’s advocates believe he provides:

“... a voice for those living in urban environments that could not otherwise express themselves, and that his work is also something which improves the aesthetic quality of urban surroundings”.

Obviously he is an artist in the tradition of the Outsider. A recurring image is of mischievous rats, about which Banksy says: “They live in quiet desperation amongst the filth. And yet they are capable of bringing entire civilisations to their knees.”

But for some, like the Keep Britain Tidy campaign, his work is vandalism like all the other graffiti.

There is an anti-capitalist (one image has Jesus crucified with a shopping bag in each hand), non-conformist, sometimes anti-police tone in his work.

Perhaps inevitably, some who share some of his world view have turned on him for being a sell out. His critics note that he has done some work for charities and big companies, including MTV, and his canvasses can fetch big money (one called Bomb Middle England shows the elderly playing bowls, which have become sputtering bombs).

Also, his book, having been released in the last few weeks, will capitalise on pre-Christmas sales. But within it, Banksy offers a robust defence of graffiti:

Graffiti is not the lowest form of art. Despite having to creep about at night and lie to your mum it’s actually the most honest artform available ... the people who run our cities don’t understand graffiti because they think nothing has the right to exist unless it makes a profit.

From Banksy’s point of view, the most ugly slogans on our high streets are not graffiti but corporate advertising and shop fronts. The criticism he attracts reveals the dilemma he faces of trying to be successful and have his work seen by as many people as possible, without it losing its power by becoming too close to the capitalist world it targets.

But Banksy does appear to have a talent for having his cake and eating it. Perhaps illustrative of this is the quotation on the back of his book in which a Metropolitan police spokesman is quoted as saying: “There’s no way you’re going to get a quote from us to use on your book cover.”