The Wall Street exception

Here's an interview with Gretchen Morgenson on the different set of rules Wall Street seems to enjoy compared to the rest of society. Seeing it as formal (law, regulation) and informal constraints (norms, tradition, worldviews), in the tradition of Institutional Economics can be valuable. What kind of informal constraints have been changed in the financial sector (and within the corresponding regulatory agencies) so that a change in formal constraints have taken place ? The interview with Morgenson reveals a shift from what is considered serious criminal offence for the rest of society - fraud - to some sort of minor mistake. As the the interviewer Chris Martenson puts it, it is change of both the "perception and the application of the rule of law".