Big Apple
"The Big Apple" was popularized as a name for New York City by John J. Fitz Gerald in a number of horse-racing articles for the "New York Morning Telegraph" in the 1920s. The earliest of these was a casual reference on 3rd May, 1921:
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.