As if we didn't have enough proof that greed makes an idiot out of every banker, and many an investor for that matter. Now we've got Bernard Madoff's spectacular fraud case to punctuate a point already clearly made by the global financial crisis. Reports of exposure to Madoff mania keep coming in from bank after bank -- from London to Tokyo. Victims include Japan's Nomura ( NMR - Get Report), France's BNP Paribas, the U.K.'s HSBC ( HBC) and Spain's Santander ( STD). Not to mention scores of U.S. investors, both individuals and charitable organizations. It was the unbelievably steady returns Madoff delivered that attracted everyone. By most accounts, Madoff consistently delivered around 10% a year, even in bad times. Clearly too good to be true, but greed makes a sucker out of even the smartest people. Apparently, Madoff was wise enough to avoid excessive returns so that even our erstwhile regulators at the Securities and Exchange Commission were duped into thinking everything was fine. Well, no surprise there. The most amazing thing about this tale is how the alleged $17.1 billion Madoff managed turned into a potential $50 billion loss for so many banks, funds and individuals. Even Jim Cramer is puzzling over that one. So I have to ask: Does anyone still doubt that the global banking and investing industry is full of greedy idiots?