Remember back in 1986, when talk-show host Geraldo Rivera hyped his live, televised opening of the "treasure vault" belonging to mobster Al Capone? Too bad it only contained a bunch of dirt. Many cried foul, claiming that Rivera used dubious, even unethical information to draw millions of viewers to his show. In the end, he was proven embarrassingly wrong -- hurting his own reputation and that of the people involved in the show.

Investor Bill Ackman isn't Geraldo Rivera. He's making a bunch of noise about bond insurers right now, but even though the insurers say he's just a ruthless short-seller, he's been spot-on -- and he's just as likely to be correct going forward.

Ackman has been hammering on bond insurers for years. He's shorted bond insurer MBIA (NYSE: MBI) ever since 2002, noting that the risk of CDOs it insured put its triple-A credit rating in peril.

Patience pays
That was nearly six years ago, and over most of that time, Ackman's call seemed poised to become another Geraldo-esque flop. MBIA and rival Ambac (NYSE: ABK) both nearly doubled in those years, continuing to crank out profits after their insurance for mortgage-backed CDOs spawned a whole new era of business.

But now that both bond insurers have come out with colossal losses, and pundits have questioned the companies' chances of survival, all eyes have turned to Ackman, who still maintains that bond insurers have plenty more pain to endure. Just last month, Ackman sent a letter to Moody's (NYSE: MCO), McGraw-Hill's (NYSE: MHP) S&P Ratings, and Fitch Ratings, calling for credit downgrades that would essentially sign the death certificate for both MBIA and Ambac.

With such dire consequences, it's no wonder that MBIA has developed a firm dislike for Ackman. But when MBIA urged the U.S House Committee on Financial Services last Thursday to "curtail short sellers' unscrupulous and dangerous market manipulation activities," and poked holes in the model Ackman uses to value the company's assets, it crossed the line into "cry me a river" territory.

Yeah, forget we said that ...
Remember, this same company claimed in its 2006 annual report that "We've had strong demand for insuring very low risk tranches of many CDO classes," only to report a fourth-quarter 2007 loss of $18 per share due to plummeting value of its "very low risk" CDOs.

Ask yourself -- whose behavior would you classify as "unscrupulous and dangerous?" The man who foresaw the future with uncanny accuracy, or the management team whose business has unquestionably fallen from grace? Who should shareholders fear -- the investor whose analysis has been dead-on, or management that has overseen a more-than-80% plunge in their company's stock in less than a year?

True, short-sellers like Ackman benefit by pointing out the company's sore spots. Then again, Google (Nasdaq: GOOG) has a similar interest in complaining about the potential online monopoly Microsoft (Nasdaq: MSFT) might form by acquiring Yahoo! (Nasdaq: YHOO). Open opinions -- positive or negative -- shape open markets, helping to prevent market manipulations.

You can't handle the truth!
As Geraldo learned in the mid-'80s, it isn't how you present your case that matters -- it's the truth of what lies inside. So far, Bill Ackman has slam-dunked both those qualifications. It's tough to keep doubting the ethicality of his short position, now that MBIA has reported a quarterly loss that nearly tripled its mid-January share price. Ackman has been right; MBIA has been wrong.

It's easy for us to point fingers at short-sellers like Ackman, claiming that they're spewing all sorts of nonsense just to drive share prices lower. Honest companies have certainly suffered such behavior in the past, and will again in the future. But when there's glaring evidence in favor of the short-seller, that person suddenly becomes nothing less than a highly rewarded whistleblower, giving other investors the chance to hear the other side of the argument before it's too late.

MBIA management fed up with Ackman's behavior should consider the old saying: "When you point your finger at someone, remember that you always have three fingers pointing right back at you."

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Fool contributor Morgan Housel doesn't own shares in any of the companies mentioned in this article. He appreciates your questions, comments, and complaints. Don't even think about shorting the Fool's disclosure policy.