Gotta add the Bond insurers to this list, Ambac, MBIA, ACA, etc.
A few years back they used to just insure stable, safe muni-bonds. They got into the business of insuring Mortgage-backed securities during the housing bubble, reaping big profits. I guess like everyone, they got a bit too greedy.
They are in process getting their pristine AAA ratings downgraded. A ratings downgrade in the bond insurance business is effectively a death sentence. The big banks will now have huge additional write downs.
We will see a worsening of the credit crunch and extending of the housing downturn.