There is summary of a nice Bloomberg article that explains out how rating agencies caused this financial crisis.
The whole world is a sucker for AAA+ rating and all the world’s investment flows towards it. However the agencies that award it, claim that its their mere opinion (backed by private research). Hence they are not liable if the ratings go wrong. No wonder, most of the Mortgage bonds that enjoyed AAA ratings defaulted without any repercussions for these agencies.
