Any lessons to learn from the Madoff con job?

The cats have been led out of the bag and everyone is shock and asking many obvious questions. Why such a big con job could be so big and go on for so long in an industry that is highly regulated? Reputation seems to be the biggest valiant in this case. Madoff has built up a reputation over the years as a man of integrity, trustworthiness, unquestionable faith and ability. And people just simply