From the NYT :
MoreThe suits will argue the banks, which assembled the mortgages and marketed them as securities to investors, failed to perform the due diligence required under securities law and missed evidence that borrowers’ incomes were inflated or falsified. When many borrowers were unable to pay their mortgages, the securities backed by the mortgages quickly lost value.
Fannie and Freddie lost more than $30 billion, in part as a result of the deals, losses that were borne mostly by taxpayers.
In July, the agency filed suit against UBS, another major mortgage securitizer, seeking to recover at least $900 million, and the individuals with knowledge of the case said the new litigation would be similar in scope.
Private holders of mortgage securities are already trying to force the big banks to buy back tens of billions in soured mortgage-backed bonds, but this federal effort is a new chapter in a huge legal fight that has alarmed investors in bank shares. In this case, rather than demanding that the banks buy back the original loans, the finance agency is seeking reimbursement for losses on the securities held by Fannie and Freddie.