How far would the media of the time go for a story or some inside information? The FBI of the '30s was concerned about newspapers and magazine personnel tapping the telephones of FBI Offices, especially the Chicago Divison. In this 1935 memo from E. A. Tamm, these fears are set out with efforts of the Bureau to code their conversations to thwart the Chicago American, and also to purposely "test" the system.
According to the Encyclopedia Of Chicago website, "In 1900, Chicago had nine general circulation newspapers when William Randolph Hearst's sensationalistic evening Chicago American appeared, followed by his morning Chicago Examiner (1902). The American upheld the raucous Hearstian/Chicago tradition of “The Front Page,” even after it was sold to the Chicago Tribune in 1956, renamed Chicago Today, and turned into a tabloid. Today died in 1974. The morning Examiner became the Herald-Examiner in 1918 and died in 1939, never able to overtake the Tribune."
The FBI 1935 Tamm memo is set out here, taken from the Dillinger file.