"But the stated opinion of those government entities asked to examine the financial crisis overall is not that no fraud was committed. Quite the contrary. For example, the Financial Crisis Inquiry Commission, in its final report, uses variants of the word “fraud” no fewer than 157 times in describing what led to the crisis, concluding that there was a “systemic breakdown,” not just in accountability, but also in ethical behavior.
As the commission found, the signs of fraud were everywhere to be seen, with the number of reports of suspected mortgage fraud rising twenty-fold between 1996 and 2005 and then doubling again in the next four years. As early as 2004, FBI Assistant Director Chris Swecker was publicly warning of the “pervasive problem” of mortgage fraud, driven by the voracious demand for mortgage-backed securities. Similar warnings, many from within the financial community, were disregarded, not because they were viewed as inaccurate, but because, as one high-level banker put it, “A decision was made that ‘We’re going to have to hold our nose and start buying the stated product if we want to stay in business.’”
Without giving further examples, the point is that, in the aftermath of the financial crisis, the prevailing view of many government officials (as well as others) was that the crisis was in material respects the product of intentional fraud. In a nutshell, the fraud, they argued, was a simple one. Subprime mortgages, i.e., mortgages of dubious creditworthiness, increasingly provided the chief collateral for highly leveraged securities that were marketed as AAA, i.e., securities of very low risk. How could this transformation of a sow’s ear into a silk purse be accomplished unless someone dissembled along the way?"
http://www.nybooks.com/articles/2014/01/09/financial-crisis-why-no-executive-prosecutions/