This post is part of a feature in which he wonder whatever happened to some notorious financial felons. See all 17.

Barry Minkow was one of the youngest people to ever take a company public in the United States. He is remembered not for that feat, but for the massive financial fraud he committed via his company ZZZZ Best Co., Inc. The stock of the carpet cleaning company once had a value of $300 million, but it all came crashing down in the late 1980s.

Minkow and a few associates successfully fooled financial statement auditors into believing the company had millions of dollars of revenue each year. In reality, the revenues were 86% below what they were reported to be. Barry took over $20 million in loans from 15 banks and several individuals in furtherance of his fraud.

He was sentenced to 25 years in prison while still in his early twenties, and ultimately spent more than seven years in prison, all of it in maximum or medium security prisons. Minkow's sentence also included $26 million in restitution. While in prison, Minkow became a Christian and devoted his life to ministry.

If you're interested in learning about the psychology and methodology of fraud -- and every investor should be -- there are two excellent videos now available on YouTube. I don't know the date on them, or what they were made for, but they're definitely worth watching.

The first is an interview with Barry Minkow, who was in federal prison at the time for the Zzzz Best fraud. The second features former Crazy Eddie CFO, Sam E. Antar.

When I listen to these former crooks explain what they did, it all sounds so easy. While their crimes occurred back in the 1980s, I wonder how much has changed.

This post is part of a series on some of the most memorable companies that have disappeared.

In the mid-1980s, Barry Minkow was the toast of Wall Street. His Zzzz Best Carpet Cleaning company, which he started in his garage at age 16, was an overnight success and, by 19, he was a millionaire. Investors flocked to buy stock in the fast-growing company that was earning millions from lucrative restoration projects.

There was just one problem: the restoration projects weren't real, the company was little more than an elaborate Ponzi scheme, and Minkow wasn't making his money cleaning carpets. He was laundering money for the mob. After a Los Angeles Times reporter broke the story on Minkow's fraud, the scheme unraveled and Zzzz Best filed for bankruptcy. Minkow was charged with pretty much every white-collar crime known to man, and he spent seven and a half years in federal prison.

But that's only the beginning of the Barry Minkow story: Minkow attended college from his cell, was paroled early at the urging of the judge who sentenced him, and became a pastor in San Diego -- not far from the scene of his crimes. Using the skills he learned committing fraud, Minkow set about uncovering it and, to date, has helped the FBI and other government agencies bust up more than $1 billion in fraudulent investment schemes: an amount far larger than the crime Minkow perpetrated.

Most recently, Minkow has gained notoriety for his accusations of fraud at leading multilevel marketing companies Herbalife (NYSE: HLF) and Usana Health Sciences (NASDAQ: USNA).

The always-insightful Herb Greenberg raises an interesting point in his latest Weekend Investor column for the Wall Street Journal: "Face it: Nobody cares much about accounting scandals anymore."

He uses the situation at International Rectifier (NYSE: IRF) as an example. After the company reported that it had fired its chief financial officer, the stock went up. The shares are currently trading at about the same price they were at before the company reported "accounting irregularities" on April 9.

Investors may have be correctly predicting that the accounting issues aren't huge -- any restatement of earnings may not be material enough to effect the value of the company.

But that's not really the point. As Greenberg writes, "Still, the market's indifference to possible fraud, no matter the size, is astounding -- especially since, at times, aggressive behavior reflects a company's culture."

Now that is precisely the point. I'm with Jim Cramer on this one: When a company's CEO or CFO resigns unexpectedly, sell the stock. If a company announces "accounting irregularities" and the stock doesn't tank on the news, take it as an opportunity to get out: Shooting first and asking questions later would have saved investors a lot of pain at companies like Enron, WorldCom, and, for you history buffs out there, Zzzz Best and Crazy Eddie.

The market appears to have developed an indifference to early warning signs of fraud, and that inefficiency could provide savvy investors with a chance to hop off the bus before it heads into a ditch.