Recent downgrades on residential mortgage-backed securities and collateralised debt obligations, and subsequent hedge fund failures and market turmoil, have led many to blame ratings agencies for the mortgage mess. Both the European Commission and Barney Frank, chairman of the House financial services committee in the US, promise hearings into the culpability of ratings agencies.

The agencies reply that accurately accounting for risk is not their job and that they are protected by the right of free speech. They point to disclaimers in their ratings that make it clear that they are paid by the companies they rate and that ratings are statements of opinion, not recommendations.