• 1997 made for TV movie about the 1927 St. Valentine Day Massacre
  
• (Below) May 1929 - Lieut. Col. Amos W.W. Woodcock visits Louisville, Ky following Feburary 27, 1929 attempt on Joe Phillip's life.
• On October 1, 1930, Senator Phillips Lee Goldborough recommended to U.S. Attorney General William D. Mitchell that SIMON E.  SOBELOFF  (Wikipedia) be appointed to succeed Woodcock.

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• The Origination and Evolution of Radio Traffic Analysis: The World War I Era
• Listening to the Rumrunners
• UNITED STATES CRYPTOLOGIC HISTORY - SERIES IV - World War II Volume 3 - German Clandestine Activities in South America in World War II

Most Americans are aware of the era of lawlessness in this country that began with the passage of the Eighteenth Amendment to the Constitution in 1919. The institution of Prohibition brought with it major law enforcement problems, whose effects continue to be felt today. Few people, however, are aware of the major role played by communications intelligence in the enforcement of the Prohibition laws. The files of the United States Coast Guard (USCG) and the Federal Communications Commission (FCC), including the files of the Radio Division of the Department of Commerce, show that radio was used on a large scale in connection with rum-running activities. The radio operations of the rum-running organizations were, in fact, comparable in terms of size, technical skill, and organization with the radio operation which would be conducted by enemy agents in World War II.

Listening in the Dark - Wiretapping and Privacy in AmericaAttorney General Harlan Fiske Stone had forbidden the use of wiretaps (Olmstead v. United States, 277 U.S. 438 - 1928), and the Treasury Department had also issued a policy prohibiting the use of wiretaps. However, in the 1920s (and thereafter) both Federal and local law enforcement sometimes ignored the law and official polices in this area when convenient. In mid-1924 Treasury Department authorities installed wiretaps on a group of bootleggers led by a Mr. Roy Olmstead.

Prohibition enforcement was conducted by the Bureau of Prohibition within the Treasury Department until 1930, when the Bureau of Prohibition was transferred to the Justice Department. While wiretapping was prohibited in both the Treasury and Justice Departments, Colonel Amos Woodcock, the Director of the Bureau of Prohibition approved of the practice, and used wiretapping liberally - ignoring the policies of his superiors..

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