Robert Mazur was a federal agent. He infiltrated Pablo Escobar's Colombian drug cartel for two years in the mid-1980s by pretending to be Robert Musella, a money-laundering, mob-connected businessman. "My role was to come across to the cartel as a credible money launderer," Mazur said. As an undercover operative, he was working with the Bank of Credit and Commerce International, a Luxembourg-based bank with branches in more than 70 countries, in order to launder the cartel's money. BCCI was known to have accounts of drug operatives, terrorists, dirty bankers and others who want to hide money. At one point, he was out at a social event in Miami with a senior bank officer at BCCI who asked him point blank, "You know who the biggest money launderer in the world is? It's the Federal Reserve, of course." That sounds like a crazy allegation, but Mazur said the banker connected the dots for him: In Colombia, it's illegal for anyone to have a U.S. dollar account. But at the state-run Bank of the Republic there is a window they call the "sinister window" or the "anonymous window." There, you can trade in as much U.S. currency as you want. The central bank exchanges it for Colombian pesos at a high rate immediately. Mazur recalls the banker asking: "What do you think happens with that cash? It gets put on pallets, they shrink-wrap it and they're sending hundreds of millions of dollars back to the Federal Reserve. Why didn't anyone ... ask where this money was coming from?"