When Ray McDaniel, president of Moody's, addressed a debate in Davos last week, the mood was so hostile that some speakers joked that he was brave to appear "without a bodyguard".

No wonder. As the credit squeeze persists, ratings agencies are being forced to downgrade thousands of securities, after failing to foresee the recent wave of defaults, particularly in subprime loans. On Wednesday night alone, Standard & Poor's downgraded more than 8,000 residential mortgage-related securities worth some $534bn (£268bn, €360bn).