This was also a documentary where I already knew a lot about it. Basically, the executives of Enron cheated everybody but themselves and they took millions of dollars. They had tons of money, and when they started losing money, they fired 20K people. The pyramid has to collapse at some point and most of the high-level people get out okay (this was from 2005, so no trials yet, just the Senate committee).
It was interesting to see that the documentary compared the traders who made illegal trades all the time to the Milgram Experiment. I also saw a comic last night that was very relevant.