Enron

One of the traders who was interviewed states he was neve confortable on the trading floor of Enron, and that he did not ask questions because he didnt want it confirmed that what he was doing was unethical. Were the traders at Enron inherently evil or can normal people be led to do bad things? Why did the traders do what they did? What crcumstances might cause normal, thical people to lose their moral compasses?