The rating agencies did a good job on the plain vanilla type of ratings. That was not the problem.
There were these securities which people were using that were using very complicated financial engineering, and very complicated legal documents, to basically, supposedly, decrease risk by diversification.
It turns out that people then realized that the rating agencies were not able to rate these things properly. There is obviously now a recognition that depending completely on rating agencies without doing due diligence yourself may be problematic.'
From the audience Q&A as reported by Bloomberg News