The banks should have to explain how they managed to buy protection from AIG primarily on securities that fell so sharply in value, says Daniel Calacci, a former swaps trader and marketer who’s now a structured-finance consultant in Warren, New Jersey. In some cases, banks also owned mortgage lenders, and they should be challenged to explain whether they gained any insider knowledge about the quality of the loans bundled into the CDOs, he says.

“It’s almost too uncanny,” Calacci says. “If these banks had insight into the underlying loans because they had relationships with banks, originators or servicers, that’s at the least unethical.”

Ryan Chittum is a former Wall Street Journal reporter, and deputy editor of The Audit, CJR's business section. If you see notable business journalism, give him a heads-up at rc2538@columbia.edu.