A little background on this that I received in email today:

If McCain wants to hold someone accountable for the failure in transparency and accountability that led to the current calamity, he should turn to his good friend and adviser, Phil Gramm.
As Mother Jones reported in June, eight years ago, Gramm, then a Republican senator chairing the Senate banking committee, slipped a 262-page bill into a gargantuan, must-pass spending measure. Gramm's legislation, written with the help of financial industry lobbyists, essentially removed newfangled financial products called swaps from any regulation. Credit default swaps are basically insurance policies that cover the losses on investments, and they have been at the heart of the subprime meltdown because they have enabled large financial institutions to turn risky loans into risky securities that could be packaged and sold to other institutions.
Lehman's collapse threatens the financial markets because of swaps.