CNBC TV host Jim Cramer has made a name for himself telling viewers how to make money in the stock market. Here's one time he might wish he'd kept quiet.

In a video originally broadcast on trading Web site TheStreet.com on Dec. 22, 2006, that resurfaced last week on YouTube, Cramer discusses at length ways he and other hedge- fund managers have been able to manipulate security prices for quick gains.

"A lot of times when I was short (stocks) at my hedge fund ... meaning I needed it (the stock) down ... I would create a level of activity beforehand that would drive the futures," the "Mad Money" host said in a broadcast that was removed from YouTube on Thursday but was available on TheStreet.com as of Thursday night. "It's a fun game, and it's a lucrative game."

Shorting stocks — selling borrowed shares in hopes of buying them back later at a lower price, thus making a profit — is a common trading tool used by hedge funds.

Cramer's comments surprised lawyers and regulators. "I think that the Securities and Exchange Commission and the U.S. attorney are likely going to have to decide whether Cramer is just a braggart, or just confessed," says Gidon Caine at law firm Jones Day.

Cramer described how he would make bets that gave the impression knowledgeable investors were predicting a stock's future. Cramer said everything he did was legal but added that illegal activity is common in the hedge-fund industry, where regulation is lax.

Cramer said some hedge-fund managers spread rumors about a company to large trading desks and the media to drive a stock price lower. He said this practice is illegal, but easy "because the SEC doesn't understand it."

He also said Research In Motion and Apple are easy targets.

Cramer didn't return messages left with CNBC or multiple e-mails asking for comment. Aaron Task, the editor at theStreet.com who moderated the interview, had no comment. CNBC declined to comment, as did the SEC and Research In Motion. Apple had no comment.

There is no indication Cramer is in any legal trouble. But he could be in hot water with peers, having referred to a "bozo" reporter at the Wall Street Journal who covers Research In Motion and saying CNBC markets reporter Bob Pisani could be used to place information.

"The way that the market really works is to have that nexus of: Hit the brokerage houses with a series of orders that push it down, then leak it to the press and then get it on CNBC," he says.

Cramer's revelations should alert regulators that it's time to take a look at hedge funds, says Lynn Turner, former SEC chief accountant now at Glass Lewis.

"They will jump on this," he says, adding that he doesn't think Cramer will face legal action.

Others hope Cramer will help fix the problem.

"I'm delighted if someone who understands how this works is truly on a reforming bent," says Michael Josephson, an ethics expert at the Josephson Institute of Ethics. He says Cramer should brief regulators on how to stop the practice.

"Few (hedge-fund) investors know what's really going on behind the door of the trading floor," he says.