NEW YORK (CNN/Money) - It may have seemed strange to see former ImClone CEO Samuel Waksal dragged off in handcuffs on charges of insider trading. But history is full of executives who have gotten into hot water because of allegations of financial impropriety -- particularly at times when the stock market turns sour after a lengthy bull run.

In the past week alone, three top Wall Street executives were charged or convicted on tax evasion, investment fraud and insider trading, all on the heels of a vicious bear market. A similar thing happened following the booming 1980s, as authoritities cracked down on an unprecedented era of greed and excess.

When the stock market's soaring and the job market's tight, many green executives get catapulted to the top. Then, when the bears come marching in, many high-flyers find themselves landing much too fast for comfort, said Buster Houschins, a managing director at Christian & Timbers, a CEO placement firm in Columbia, Md.

"What happened is the market expanded so fast that people went into leadership roles too soon without the proper seasoning," Houschins said. "What happened at ImClone is another example of an executive who didn't have 'It.' "

The longest bull market in memory came to a screeching halt in early 2000. As the major indexes came crashing to earth, so did many of the companies whose stocks had been the air in the bubble. And soon after, corporate executives, money managers and even some of Wall Street's most venerable firms came tumbling into the long arms of the law.

Here is a look back at some of the bigger cases.

Samuel Waksal

• Samuel Waksal of ImClone. Four FBI agents arrested Waksal Wednesday on six counts of securities fraud, two counts of conspiracy, and one count of perjury. Waksal, a friend of celebrities such as Mick Jagger and Martha Stewart, was charged with tipping off people to sell their ImClone stock right before regulators rejected the company's application for a new cancer drug.

Denis Kozlowski

• Dennis Kozlowski, former CEO of Tyco. Kozlowski was apparently an art lover, but it looks like he may have tried to get it tax-free. He was charged June 5 with cutting illegal deals to avoid more than $1 million in taxes on rare works by Renoir, Monet and other artists. The widening criminal probe includes claims the company bought homes and artwork for executives without reporting it. Tyco's (TYC: Research, Estimates) stock has plunged about 80 percent this year.
• Alan Bond, president and chief investment officer of Albriond Capital Management. Bond, once a regular on "Wall Street Week With Louis Rukeyser," is behind bars after he was found guilty Monday of investment advisory and wire fraud. A graduate of Harvard Business School, he is one of a handful of African-Americans to make it to the top in money management. He was accused of defrauding clients by sending unprofitable securities trades to their accounts while directing most of the profitable ones to himself. He faces a maximum of 45 years in jail when he is sentenced Sept. 9.
• Merrill Lynch. One of Wall Street's premier institutions came under fire from New York State Attorney General Eliot Spitzer in April, when Spitzer accused the firm's analysts of recommeding questionable stocks to the public to benefit Merrill's investment banking arm. Although Merrill Lynch admitted no wrongdoing, the company has agreed to pay $100 million in fines as part of a settlement.
• Former Kmart CEO Chuck Conaway and President Mark Schwartz. Several executives of bankrupt retailer Kmart (KM: Research, Estimates), including Conaway and Schwartz, are a little lighter in the wallet these days. The company in May said it was suspending severance pay for the executives and launching a probe into their activities. The FBI also announced in May that it was investigating Kmart, a day after the company reported a record loss of $2.42 billion for its latest fiscal year.

Kenneth Lay

• Kenneth Lay, Jeffrey Skilling and Andrew Fastow of Enron. While nobody at the bankrupt energy trader has been charged with a crime, former Enron CEOs Lay and Skilling and former chief financial officer Fastow found themselves in the hot seat in Washington before panels of angry members of Congress. The Securities and Exchange Commission and the Department of Justice are investigating, and lawmakers have proposed dozens of bills on everything from executive stock options to 401(k) reform.

"Enron's quick collapse touched off more aggressiveness by regulators and prompted them to dig more deeply into executive dealings," said Alan Ackerman, senior vice president and market strategist at Fahnestock & Co. in New York.

Of course, some corporate top dogs wound up in hot water before the bear market began. In some of those cases, the boom times bred an atmosphere of anything-goes. In others, troubled companies went under the microscope and new improprieties came to light.

Steve Madden

• Shoe designer Steve Madden. Madden pleaded guilty to stock fraud and was forced to step down from his company temporarily. He had been charged with illegally manipulating 22 initial public offerings, including his own company's. He paid a $7.8 million penalty to settle charges with the SEC and was sentenced to 41 months in prison.
• "Chainsaw Al" Dunlap, former Sunbeam chief. Dunlap, whose nickname stems from his penchant for cutting thousands of jobs, was fired by the struggling company in 1998. The SEC in 2001 filed suit against Dunlap and other executives for fraud that cost the company billions of dollars. It also surfaced that Dunlap had been accused of fraud at a company he headed in the 1970s. Dunlap apparently withheld that information from his resume as he rose up the corporate ladder.

Many old-timers on Wall Street scoff that capitalism always breeds people with a thirst for more -- more money, more power, more possessions. Whatever the cost. In the 1980s, corporate greed took on a life of its own. Who can forget Gordon Gekko, the loathsome character with the lizard-like name from Oliver Stone's 1986 movie "Wall Street," who valued money over everything else?

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Two decades later, such greed is still legendary, and Ivan Boesky, Michael Milken and Charles Keating are still household names.

• Ivan Boesky, rogue financier. Back in the mid-1980s, Boesky was engaging in ultra-risky arbitrage until the SEC caught up with him. He paid a $100 million fine and pleaded guilty to insider-trading violations in 1986. He was later sentenced to three years in prison.

Michael Milken

• Michael Milken, head of the junk-bond operation at defunct Drexel Burnham Lambert. Milken was a Wall Street legend when he oversaw the junk bond business at Drexel. But in April 1990, he pleaded guilty to violations of securities laws. Drexel went bankrupt and high-yield investing had a black eye for years. After the case was settled in 1991, Milken paid more than $1 billion in fines and served two years in prison. He later agreed to pay a $47 million fine to the SEC for acting as a securities broker in several deals.
• Charles Keating, chief of Lincoln Savings & Loan. Keating was one of the most renowned characters in the 1980s collapse of the savings & loan business. He was convicted of securities fraud for allegedly looting the S&L and bilking investors of $200 million. He served more than four years in prison before the charges against him were thrown out. After extensive legal wrangling, Keating later agreed to plead guilty to four felony counts in a deal to stay out of jail.

This list, obviously, doesn't stop there.

Long before Charles Keating put on a prison jumpsuit, Wall Street bigwigs were getting into trouble for the sake of the almighty dollar. And long after Samuel Waksal gets through explaining himself to the authorities, more are likely to follow.  

-- With additional reporting from Staff Writer Meghan Collins