(watch ticking) arlan galbraith who called himself "the pigeon king" convinced hundreds of american and canadian farmers there was good money to be made raising the birds for food. >> and everybody we talked to said this guy was--he was on the up and up. nobody had a bad word to say about him. (watch ticking) >> stahl: welcome to "60 minutes" on cnbc. i'm leslie stahl. in march 2009, bernard madoff pleaded guilty to perpetrating what's believed to be the largest financial fraud in history. he received the maximum sentence for his crime, 150 years in prison. but while madoff is behind bars, there's still much we don't know about the scam which involved, by some accounts, a fraud of more than $50 billion. investigators are still trying to figure out who was involved and where the money went. this edition features some of the people most intimately familiar with madoff's schemes: irving picard, the court-appointed trustee charged with finding the missing money, some of the crooked financier's victims and the man who figured out madoff's crimes out before anyone else, harry markopolos. plus