She explains this very clearly in this article.

“The financial crisis resulted largely from the use of credit derivatives. How?

We saw them hide risk and create a lot of leverage in the global financial system in securities and securitization, where one bad mortgage could be levered up to be in numerous different deals. That kind of malicious leverage had a big impact. A lot of fraudulent securitization provided funding for corrupt lending. Had we not done that, our housing crisis — and the situation we still have today — wouldn’t have been nearly as bad. Derivatives helped supply the leverage to inflate the bubble.

Are they still dangerous?

Today we see a credit derivatives market that is poorly understood by regulators and even by many of the banks who are participating in the market. And there just doesn’t seem to be a will to clean it up.

What should be done about sovereign credit default swaps?

When they were [first] sold, the hype was that they were useful hedging tools. The result is that they have been a game for speculators more than a hedge for hedgers. Speculators can go in and depress sovereign debt just when a sovereign needs to roll over debt — and of course the price of the credit default swap will shoot up. These games create temporary dislocations in the market. Given that we haven’t driven speculators out of the market, it’s a good idea to ban credit default swaps altogether.

What else can be done now to try to prevent another financial crisis?

In terms of money flow in the U.S., we have to write down debt and maybe have some sort of debt forgiveness. That’s a radical thought, but some people will never be able to get out from under their debt in their lifetime. Going forward, we have to make responsible loans.”
http://www.advisorone.com/2012/04/25/finding-the-culprits-of-the-crisis?t=economy-markets&page=4

well he did not beat up a mob of 50 for a start. With helpfrom his sone he beat up 7, the rest fled