Fred Radtke is a polarizing guy. I don't know anyone who's a fan, but I know there are plenty who'll defend him. Even T-shirt company Dirty Coast took a side with a "Gray is Graffiti" shirt. Radtke is known as The Gray Ghost, who for years has "grayed out" graffiti across New Orleans, using a team of roll brushers (Operation Clean Sweep) and buckets of gray paint to cover up street art — whether it's unsightly tags on business property, or commissioned neighborhood art or Banksy's post-Katrina stencils.

In the new documentary Vigilante Vigilante, filmmakers explore the dynamic of street artists defying the law and injecting some color and commentary into urban landscapes, and their vigilante opponents, who, like Radtke, wield cover-up paint and paint scraping tools to remove graffiti artists' work — "do graffiti, to eliminate graffiti," as the film says. In San Francisco there's the Silver Buff. In Los Angeles there's the Graffiti Guerilla. And in New Orleans, there's Radtke. "We have a problem in this city," he says in the film's trailer

The ideologies are paired against each other — noted street artist Shepard Fairey ("OBEY") says "It's not about legal or illegal, it's about no barriers between the public and the art," while "broken windows" theorist James Q. Wilson suggests graffiti welcomes urban decay.

The film premieres in San Francisco later this month. Check out the trailer below: