When Ivan Boesky was busted for insider trading in 1986, he quickly became a household name, as Wall Street watchers marveled at the audacity of his trading exploits.

His rise and fall were documented in bestseller "Den of Thieves" and his “greed is good” philosophy became a hallmark for a generation of stock traders after it was channeled by fictional corporate raider Gordon Gekko in the movie Wall Street.

Now, a new symbol of the culture of greed could soon emerge as billionaire hedge fund manager Raj Rajaratnam faces charges that, like Boesky, his huge fortune was built on inside information rather than hard work and market smarts.

Rajaratnam, who founded the Galleon Group hedge funds, is charged with eight counts of securities fraud and four counts of conspiracy in the case that spans the last three years. The Securities and Exchange Commission also has filed civil claims against him and six others. Prosecutors contend that Rajaratnam used a network of sources to wheedle information not available to the average investor, profiting to the tune of $20 million.

Legal experts say that in order to prove insider trading, the government will need to establish that Rajaratnam knew the information he was getting was not public, something that’s not always easy when the recipient is a fast mover like Rajaratnam, who likely talks to hundreds of sources a day. There is a fine line between good old fashioned shoe leather research and illegally obtaining information.

“The most difficult aspect of insider trading to prove is the defendant’s intention to commit a crime,” said Robert G. Heim, former assistant regional director of the SEC’s New York office. "From the defendant's perspective, often times there are questions about whether the information was actually inside. It’s a gray area. It can come down to who made the tip, and did the person trading know it was supposed to be confidential.”

Like Boesky, Rajaratnam was brash, making multi-million dollar trades just days before information broke that moved the market. But federal prosecutors and SEC lawyers have something against Rajaratnam that they didn't have on Boesky: telephone wire taps.  According to federal prosecutors, this is the first time that court approved wire taps have been used in an insider trading case.

“The government here has a lot more than simply circumstantial evidence,” said John Coffee, a Columbia Law School professor. “They have his own voice on record.”

And those words could go a long way toward convicting the hedge fund magnate, depending on how he chose them. At least one of Rajaratnam’s co–defendants, New Castle Funds trader Danielle Chiesi, all but admitted she knew what she was doing when she compared herself to Martha Stewart, the domestic maven famously arrested for trading on insider information.

"I swear to you in front of God...You put me in jail if you talk. I'm dead if this leaks. I really am...and my career is over. I'll be like Martha f---ing Stewart," Chiesi told an unnamed person, according to the complaint against her.

Stewart was convicted of lying to investigators about a stock trade and obstructing justice and served time in prison.
“Admission is the hardest part of the prosecutors’ case, and she just made it for them,” Heim said.

Another difficult aspect of the government’s case against Rajaratnam is proving that he had promised to pay off his tippers in some way. Proving the quid pro quo is another essential element of the case, Coffee said.

“The government doesn’t have an old fashioned insider trading case unless they can show there is some promise of a benefit in return for the information,” Coffee told FOX Business.

But Brad Simon, former Assistant U.S Attorney for the Eastern District of New York, said the government’s case will not suffer if it can’t prove Rajaratnam was paying for his information.

“If there were payoffs to get the information that is pretty damning, but what’s more important is if it’s clearly information that would have been obtained as a result of some illicit action on somebody’s part,” he said.

Like Boesky, Rajaratnam clearly did not need the money and like Boesky, if convicted, Rajaratnam’s Wall Street career is likely over.  These days, little information about Boesky's whereabouts is available.  He was banned from working in finance and according to one blog, he is broke and living on alimony payments from his ex-wife.  Another report has him in Europe, keeping a low profile. 

Earlier this week, Galleon announced it would fold under the weight of the scandal. In a letter to employees, Rajaratnam said Galleon will "conduct an orderly wind down" while "various alternatives for our business" are explored.

Rajaratnam is out of jail after posting $100 million bail.