He may pepper his speech liberally with "Hallelujahs", "Amens" and the language of the pulpit, but Reverend Billy is not a real preacher. He is the character created by Bill Talen, a New York, performance activist (part performance artist part political activist), who is fighting the good fight against the evils of corporate imperialism armed with a dog collar, a megaphone and his wits.

Dietmar Post's hour-long, DV documentary follows the reverend preparing for and performing three separate "actions". The first is at the biggest Starbucks coffee store on Manhattan island, the second is at a Disney store in New York and the third, incongruously, is saving a historic house, where poet Edgar Allan Poe wrote his famous poem The Raven, from destruction.

With a posse of activists and videographers in tow, he swoops into a Starbucks and begins to rail loudly in singsong voice at the blandness inflicted upon his neighbourhood by the chain stores. "We're drowning in a sea of identical details," he booms through his megaphone, while a befuddled Starbucks employee tries to usher this madman out.

Now on the entrance step of Starbucks, flanked by a group of four stone-faced NYPD officers, he decries the fact that the previous café and its "famously abusive waiters" have been replaced by this "ersatz café... where they turn Bob Marley music into musac."

Talen believes that to bring about change you have to make a fool of yourself, you have to start "nervously doing something awkward at first."

Like many crusaders not much holds him back. His voice or his megaphone break before he steps down. Or the boys in blue haul him away. This time it is the megaphone, which gives his choir The Church Of Stop Shopping a chance to break into a rousing gospel number about, you guessed it, not shopping.

These bizarre stunts are entertaining and the handheld camera in dogged pursuit offers a sense of immediacy. However, by the second section which takes place in a Disney store with a stuffed Mickey toy nailed to a crucifix, I found myself hoping the camera would step back and we would be offered more circumspect and in-depth comment about the reverend and perhaps about the nature of protest itself.

But there are only passing comments from members of the reverend Billy activists. We are told that the reverend has influential friends in the media, but we don't meet any of them, or even hear readings of their editorials. This might have provided some needed background to this colourful character. There is also no comment from the corporations addressed by these actions or even mention that they declined to comment. Instead the camera remains glued to the reverend, going where he goes and listening, often over his shoulder, to his preaching.

By the third action, to prevent Edgar Allan Poe's house being pulled down, by New York University of all organisations, you have accepted that the film is sticking to this vein.

The reverend (with pulpit) ensconces himself with a musical group of friends on a ledge in the empty Poe building, from where he decries its destruction to the gathering crowd below. Again, the reverend's theatrical brand of protest is inspiring. There is a memorable scene after he has been led by the NYDP down to the sidewalk, where he politely and firmly stalls a grim-faced cop who wants to take him back to the slammer. Meanwhile, "Quoth the raven nevermore!" echoes around him from the congregation of folk reading Poe's poem.

In terms of the film's structure, this particular section only tenuously holds together with the previous two actions. Standing against the corporations appears to be the thread.

You can't help feeling that opportunities were missed to fill us in more on Reverend Billy's story. A less in-your-face approach and more informative style, with third person commentary, would have complemented the strengths of this fly-on-the-wall reportage.