If you've seen this brilliant film about street art -- or even if you haven't -- there's something provocative to consider in the opening montage.

The film, credited to famed British street artist Banksy, is mostly about work like the kind he does: Witty, boundary-breaking stuff, as often as not painted or posted on blank or otherwise untended spaces, like monolithic retaining walls or the sides of abandoned buildings. Think the work of two acclaimed street artists with recent credits in Pittsburgh -- Shepard Fairey and Swoon (both featured in Exit) -- and you'll get the idea. Even people who hate "graffitti" would have to agree that work like these artists' is well-crafted. They might even grudgingly admit such work improves the desolate spaces it is foisted upon.

But that opening sequence, a rapid-fire succession of scenes of street artists at work, isn't just about the clever Banksys of the world. Intercut are images of what even a street-art appreciator like me would call vandalism: Dudes spray-canning a wavy line down the length of a building, or scrawling an artless tag. The sort of thing it seems some young man or other gets busted, fined and even jailed for every year or so in Pittsburgh.

Exit isn't a movie about taggers -- it's about artists like Banksy himself, who has done conceptual paintings on the Palestinian side of the West Bank's Israeli wall (like a trompe l'oeil of a hole in wall that seems to provide a view of a tropical beach). The montage, though, recognizes no such distinction. The taggers are given equal status.

On the one hand, this doesn't surprise me much. In Banksy's highly recommended book Wall and Piece, he lays out some of his philosophy. It includes a critique of how corporations can buy public art space (in the form of billboards and other adverts), but anyone without money who tries to claim a few eyes for the vox populi is criminalized. (The film, moreover, is at heart a critique of the commercialization of art.)

On the other hand, that Banksy would equate taggers with artists surprises me a little, because in his book, he writes, "All artists are prepared to suffer for their work. Why are so few prepared to learn to draw?"

And indeed, it's the artfulness of work like Banksy's, combined with who-and-where of the victim (a Coke billboard, or some poor shlub's shop window?) that seem to me to determine whether something's guerilla art or merely vandalism. 

Exit Through The Gift Shop plays nightly through Thu., July 8, at the Regent Square Theater.