 Korshak's law practice brought him into contact with many mobsters, such as Al Capone, Frank Nitti, Sam Giancana, Tony Accardo and Moe Dalitz.His services were used by the upper ranks of both legitimate and illegitimate business in the United States.Korshak numbered among his friends many Hollywood celebrities and leading figures in the entertainment industry, including MCA/Universal chiefs Jules C. Stein and Lew Wasserman, entertainment lawyer Paul Ziffren (the driving force behind bringing the 1984 Olympics to Los Angeles), MGM chief Kirk Kerkorian, Gulf+Western founder Charles Bluhdorn, Frank Sinatra, Ronald Reagan, William French Smith (labor attorney and future United States Attorney General), California governor Edmund "Pat" Brown and his son, California governor Edmund "Jerry" Brown, future Governor of California Gray Davis, producer Robert Evans, Warren Beatty, Barron Hilton and Hugh Hefner.