Mark Cuban's battle with the SEC will be nasty

Billionaire Mark Cuban, who relishes a good fight with everyone from NBA referees to readers of his popular blog, has got a doozy on his hands: now he's fighting the Securities & Exchange Commission's accusations of insider trading.

At issue is whether the 50-year-old entrepreneur improperly sold shares of Mamma.com Inc. in 2004 after being told by the company's chief executive about its plans for a private share offering. The SEC argues that Cuban avoided more than $750,000 in losses by selling shares in the company, which is now called Copernic Inc.