In recent years, the subject of leaks of classified information from U.S. Government agencies has received a great deal of attention. This is not a new problem; I have seen references to such leaks as early as World War I. In the early 1960s, however, the Department of State suffered a spate of leaks. The problem was significant enough that President John F. Kennedy discussed the matter with Under Secretary of State George W. Ball (the Department’s #2 official). In response, the Under Secretary personally prepared the following memorandum to the President discussing how to deal with the issue.
Along with the memo, Ball sent an 8-page outline of the proposed seminar (best copy available).
The problem of leaks has never gone away. Attempts by the Nixon Administration to deal with that issue led to some of the Watergate-era abuses.
Source: Under Secretary of State George W. Ball to President John F. Kennedy, November 8, 1963, file PR 11, 1963 Subject-Numeric File (NAID 590618), RG 59: General Records of the Department of State, National Archives.