Big Apple
"Big Apple" is a nickname for New York City. It was first popularized in the 1920s by John J. Fitz Gerald, a sports writer for the "New York Morning Telegraph". Its popularity since the 1970s is due in part to a promotional campaign by the New York tourist authorities.
Joseph D. Pistone
Pistone was selected to be an undercover agent because he was of Sicilian heritage, fluent in Italian and acquainted with the mob from growing up in New Jersey. He also said that he did not perspire under pressure and was aware of the Mafia's codes of conduct and system. The operation was given the code name "Sun-Apple" after the locations of its two simultaneous operations: Miami ("Sunny Miami") and New York City ("The Big Apple"). After extensive preparation including FBI gemology classes and again using the alias Donnie Brasco, he went undercover as a jewel thief.