The search for scapegoats in the worst financial crisis since the Great Depression is under way. As one financial group after another has collapsed, wiping out thousands of billions worth of value for investors, a plethora of investigations by prosecutors and regulators has been launched.

Federal officials have opened investigations into at least 25 large companies, including Lehman Brothers, the collapsed investment bank; Fannie Mae and Freddie Mac, the mortgage financiers taken over by the government; and Washington Mutual, the biggest bank to go under in US history.