http://www.safehaven.com/article/37748/paying-for-the-past-insight-from-lindsey-fisher-and-greenspan

 Greenspan: "We're way underestimating our debt, as of now, largely because we are not including contingent liabilities... What is the probability, in today's environment, that JPMorgan would be allowed to default? The answer is zero or less. Now that means that that whole balance sheet is a contingent liability. To be sure, that while it's contingent there's not interest payments. But ultimately that overhangs the structure, because we in so many different ways have guaranteed this, that and the other thing. It's not only Fannie and Freddie, but it's a whole series of financial institutions. And, regrettably, it's also non-financial institutions. I was very much concerned when we started to guarantee everyone as being too big to fail. But at least it was in the financial area. As soon as we moved over into General Motors and various other non-financial organizations, I said what is the contingent liability of the United States... What the three of us are talking about, the path we are currently on is not going to be easily resolved. It's going to be very difficult... The sooner we get to it the better. But I see no evidence that we're moving in that direction."