We are all now, it seems, street.  Or can be.

For sufficient pennies, that is—but in a world where Brad Pitt and Angelina Jolie lavish £200,000 for Banksy’s images of the urban subaltern, can the subversive retain its character, once become an investment? With its practitioners now laughing all the way to the Banksy, is subversion, vicarious and vetted, a commodity in a futures trading market for those yoked to workaday lives?

Hollywood, which might know something about the revenues from selling subversion and its images, feted Banksy in February as one of three Brits nominated for the Oscar category of Best Documentary. The fragility of the subversive lingers in our thoughts about it.  The Daily Mail, that outpouring of national id, in July 2008 led with a headline, ‘Graffiti Artist Banksy Unmasked…As a Former Public Schoolboy From Middle-Class Suburbia’. Never mind they’d not actually found him:  the moral was clear, a message from a posh pretentious painter of streets need not disturb us in our chips.

But Banksy’s so far cleverly eluded them all, Associated Newspapers to the Academy Awards. His documentary inaugurated a new category of ‘possible prankumentary’, with gallerist Steve Lazarides saying ‘I don’t know who the joke is on, really. I don’t even know if there is a joke.’ On Oscars night driving the drama, and absent amidst rumours he would attend, he was Hamlet’s ghost. The singer Justin Timberlake, profoundly conventional even by the standards of a boyband pop star, claimed to have been him.

Street art, and sharks preserved in formaldehyde, are the two genres to enter art history books in our lifetimes. In common with the shark, it is also at the moment chiefly British. Samantha Cameron selected a painting from street graffiti artist Ben Eine for her husband to give Obama during his first White House visit.  Perhaps Banksy was busy that day.