Sam Giancana
Sam Giancana and Murray Humphreys both topped the FBI's Top Hoodlum list, "Top Hoodlum" being a program put into operation in 1957 for the purpose of combating organized crime and the Mafia in particular. When Chicago FBI agents under the leadership of William F. Roemer finally discovered that a second-floor tailor shop on North Michigan Avenue, in the heart of what is now "Magnificent Mile", was a frequent meeting place for such Outfit notables as Humphreys, Tony Accardo, Sam Giancana and Gus Alex, the FBI painstakingly installed a hidden microphone in the shop after hours. "One microphone was worth a thousand agents", said Roemer, fondly remembering the bug they christened, "Little Al." "Little Al" remained in place undetected for five years, and gave the FBI invaluable knowledge about the inner workings of the Mafia.