Karl Marx is Back

And the documentarians have got him!

"Black Gold," now being screened at festivals and art houses, is the latest in a growing genre of documentary films shaking up the business world. They are taking critiques of corporate power that would once have been the province of newspapers and magazines to movie theaters and DVD shops, where they're finding an increasingly receptive audience.

The trend, which started with "Roger and Me" in 1989 and more recently featured "Super Size Me" and "Enron: The Smartest Guys in the Room," is forcing some corporate targets to counterattack — and, some say, even change business practices — to dodge claims of unfair wages, unhealthy products or environmental degradation.

"When you're talking about a documentary, it's something that's being presented as if it's fact, so that's a huge problem for companies," said Paul Argenti, a professor at Tuck School of Business at Dartmouth University.

....This year's "Iraq for Sale: The War Profiteers" from director Robert Greenwald was bankrolled by thousands of individual donors who responded to a fundraising e-mail from the filmmakers.

Despite the relatively small budgets, many of the films have drawn big attention.

....Even less broadly distributed documentaries are finding wider interest than a liberal screed in The Nation or an expose in The New York Times Magazine with similar ideas might reach.

....Web sites for documentaries like "Black Gold" and "Wal-Mart: The High Cost of Low Price" list dozens of screenings each month at repertory theaters, universities and churches where they're presented by advocacy groups and often followed by discussion sessions.

"They become events in themselves," Nick Francis said.