The beneficiary of a credit default swap on a company's debt may get a huge payoff from the issuer of the CDS if the covered company defaults on its debt.  It is reported that CDS holders of Lyondellbasell are trying to force it into bankruptcy for just that reason.  The value of CDSs outstanding on the debt of a big company like GM can be much larger that the face amount of the debt because one does not have to own the debt to enter into a CDS.  AIG was a big issuer of CDSs, and it would not be shocking to learn that AIG (and, therefore, US taxpayers) would be one of the biggest losers if GM is not able to avoid bankruptcy.