What can investors learn from the unmasking of Jim Cramer?

Jim Cramer plays on the worst instinct of investors: greed. He understands how desperate investors are to find that one guru who can tell them how to make "fast money" by picking stocks that only go in one direction -- up.

On the surface, he has the right credentials. He was a successful hedge fund manager, who made a fortune on Wall Street, although it now appears that some of his gains were obtained through the use of highly questionable practices. His hyperkinetic personality and over-the-top antics contributed to the perception he must really know how to pick stock winners.