Frontline: Black Money

Slush funds, front companies and secret payments are just a few of the illegal tactics multinational companies are using to fatten their wallets -- and increasingly, investigators are on to them, as this special edition of "Frontline" illustrates. Investigative journalist Lowell Bergman shows how the U.S. Justice Department is working with allies around the world to crack down on the billion-dollar business that international bribery has become.