SLJames:
The "top of the world" phrase was from 1949's "White Heat", in which James Cagney played "Arthur 'Cody' Jarrett", a FICTIONAL psychopathic criminal with a mother complex.
"Machine Gun Kelly" (1948), starring Charles Bronson as "George R. 'Machine-Gun' Kelly", was based upon real life. Kelly, whose real name was George Kelley Barnes, was small-time bank robber and bootlegger who, among other things, orchestrated the kidnapping for ransom of Charles F. Urschel, a wealthy Oklahoma businessman. The kidnapping took place at 11:15 P.M. on Saturday, July 22, 1933, while Urschel and his wife were entertaining friends, Mr. and Mrs. Walter R. Jarrett.
Both men were kidnapped, as the kidnappers did not know which one was Urschel. Mr. Jarrett was released, returning home at 1:00 A.M. the next day, July 23rd. Urschel was held for $200,000; the ransom was paid on July 30th, and Urschel was released the following day.
Kelly's gang was eventually captured in August and September of 1933.
Kelly is probably best remembered for inventing the term "G-Man" (short for "government man", which to him meant a revenue agent--that is, an operative of the BATF). Upon his capture, he raised his hands and shouted "Don't shoot, G-Men!". Popular culture uses the term as a euphemism for FBI agents, but technically, it could be used as a slang term for any Federal law-enforcement officer.
Twenty-one people were convicted in the case, receiving the following sentences: 6 life sentences (including Kelly); the ones who did not receive life sentences received jail time totalling 58 years, 2 months, and 3 days.
Kelly died in the federal penitentiary at Leavenworth, Kansas, on July 17, 1954, of a heart attack; his wife, Kathryn, was released from prison in Cincinnati in 1958.
End history lesson.

--Foreigner