(FORTUNE Magazine) – Power-crazed media moguls blackmail members of Congress. An agribusiness giant poisons an Indian reservation. A famed Texas CEO hires a hit man to gun down his ex-girlfriend.

If you missed these stories from the world of commerce, you haven't been watching television lately. They're examples of an unmistakable trend: the rise of corporate villainy in prime time.

For further evidence, peruse a new study of TV programming from the Media Research Center, a conservative think tank in Alexandria, Va., whose researchers watched a mind-numbing 863 sitcoms, dramas, and TV movies broadcast by ABC, CBS, NBC, and Fox. Their findings: Business people tend to be portrayed as venal and unscrupulous. They engage in criminal behavior. And, as a group, corporate types commit more murders on TV than any other occupational category--even career criminals.

Heroic CEOs, meanwhile, are scarce. "You see lawyer heroes and cop heroes, but it's hard to do a TV show about job creation or investment," laments Tim Lamer, co-author of the report, titled "Businessmen Behaving Badly."

This isn't entirely unexpected. Corporate types have plotted and schemed their way through prime time at least since the late 1970s, when Larry Hagman played that human oil slick J.R. Ewing on the nighttime soap opera Dallas. What's noteworthy is that today's TV businessmen resort to extremes in pursuit of shareholder value.

Take the fictional Agri-Feed Co. depicted on the CBS drama Walker Texas Ranger. Its CEO foists an untested feed additive onto an Indian reservation, murders his corporate counsel, wipes out dozens of Indians, and sends in a private army to cover up the mess. "Billions in future profits, for the lives of a few Cherokees," he sums up. Or consider the warring media moguls in the HBO satire Weapons of Mass Distraction, who bribe politicians and turn loose the full frenzy of their tabloid TV shows and newspapers to destroy one another. Compared to these guys, Rupert Murdoch is a pussycat.

In a particularly brazen bit of business-bashing, the cable network Lifetime is currently airing a "fact-based" movie called Two Voices about two women who fought to expose the dangers of silicone breast implants. The villain is a real corporation: Dow Corning, a breast implant-maker now in bankruptcy, accused by the filmmakers of knowingly selling an unsafe product, callously ignoring the complaints of women, and perhaps even spying on its critics. "How do these guys at Dow Corning sleep at night?" asks one of the noble heroines in this morality play. Her husband explains, helpfully, "Dow is like any other corporate entity. Their board answers to the stockholders."

The truth is more complex, to put it mildly. The FDA and the Justice Department investigated Dow Corning and found that it disclosed all known safety risks associated with implants. What's more, mainstream science has debunked the central claim made by the women, that silicone implants cause debilitating disease. Lifetime President Doug McCormick concedes the movie is unbalanced: "These women felt they were done a great disservice by these companies. We agreed to tell the story from their point of view." Dow Corning CEO Richard Hazleton says the film is filled with "cartoon-like portrayals," but he's not suing. To its credit, Lifetime will follow Two Voices with a half-hour documentary that corrects some but not all the distortions.

One reason companies get a bad rap on TV is that big business hasn't gone to the trouble of lobbying Hollywood, unlike other groups. Latino and African-American organizations complain when the networks show too many Hispanic drug lords or black gang leaders, while Arab-American groups object to the stereotyping of Arabs as terrorists. Writing a Mafia don into a script is a sure way to arouse the ire of Italian-Americans.

And sponsors, who could make a difference, focus on other issues. Major TV advertisers like Chrysler, Kellogg, and Wendy's stay away from programs with too much sex or violence, but they say that screening shows for social messages would be too complicated.

The networks cite another reason why they portray businessmen as heavies: they're credible in that role. If viewers didn't accept the idea that CEOs lie, cheat, and steal, they wouldn't be shown doing so. "We need villains," says an unrepentant network insider. "And if we portray businessmen as not caring about society or their employees, would we be all wrong?" Maybe not, but the studios and the networks ought to remember who's buying their lunch.

--Marc Gunther