"The Justice Department plans to file civil fraud charges against the nation’s largest credit-ratings agency, Standard & Poor’s, accusing the firm of inflating the ratings of mortgage investments and setting them up for a crash when the financial crisis struck. The suit, expected to be filed as early as this week, would be the first significant federal action against the ratings industry, which during the boom years reaped record profits as it bestowed gilt-edged ratings on complex bundles of home loans that quickly went sour. The high ratings made many investments appear safer than they actually were, and are now seen as having contributed to a crisis that brought the financial system and the broader economy to its knees."

U.S. Plans to Sue S.&P. for Ratings on Loan Bundles - NYTimes.com