In the latest chapter of legal drama for Kevin Trudeau, a federal jury in Chicago found him guilty of criminal contempt for violating a 2004 consent decree with the Federal Trade Commission.

Under the 2004 agreement, Trudeau promised not to directly or indirectly produce and broadcast any deceptive infomercials that misrepresented the contents of any book. But in December 2006, Trudeau began airing infomercials to promote his new book The Weight Loss Cure "They" Don't Want You to Know About.

According to the FTC, the infomercials made multiple deceptive claims about how the weight loss plan is "easy to do, can be done at home, and ultimately allows readers to eat whatever they want." In three half-hour infomercials, Trudeau claimed he had discovered a secret and permanent weight loss plan that was suppressed by food companies and the government in an effort to keep people fat. The program did not require any exercise or dieting, he said, and users could eat as much of whatever food as they wanted.

But the diet was actually a grueling regimen, the government said, featuring a limited 500-calorie-per-day diet and the use of prescription hormones. "He made the book sound way better than it actually was," prosecutor Marc Krickbaum told the jury during his closing argument. "If he told the truth, that book wasn't going to sell nearly as well than if he lied."

Trudeau's attorney Thomas Kirsch countered that the government, by calling only two witnesses and failing to establish that Trudeau's misstatements were intentional, had failed to prove its case. "Watch any television commercial for any product – it's the views and opinions of the persons who are making and selling the product," Kirsch said to jurors. "That's what advertising is."

After deliberating for less than one hour, the jury found the 50-year-old Trudeau guilty. He was taken into custody and now faces a potential prison term.

The FTC has also pursued a civil suit against Trudeau. Six years ago, he was fined $37 million in that case; since then, prosecutors have failed to recover any of the money. Trudeau says that he has no money, while the government contends he has hidden assets.

Why it matters: A sentencing date has not been set for Trudeau, who faces an uncertain prison term. Criminal contempt does not carry a maximum sentence, so his prison stay will be within the discretion of the federal judge overseeing his case, U.S. District Court Judge Ronald Guzman. Trudeau has not endeared himself to the judiciary throughout the litigation process. He was jailed on two separate occasions for lying about his assets. And after his fine was imposed, Trudeau urged his supporters to e-mail the judge in protest. As a result, the judge's e-mail account crashed.