Most Americans still associate the idea of illegal informants or spies with people like the Rosenbergs, who leaked nuclear secrets to the Soviets. Indeed, articles on famous spies before about 1970 show that most high profile cases were working for the Soviets.
Thus, before the 70s, a spy was generally thought of as a person who shared secrets, often military, with a perceived enemy who could be expected to use those secrets to harm America, and the expected or potential harm was usually of a military nature.
Beginning with the Daniel Ellsberg case in 1971, the unofficial definition of “espionage” and “spy” started to shift subliminally in the minds of Americans, along with the unofficial definition of “enemy,” in keeping with the granting of Most Favored Nation status to China. In the broadest terms, the shift could be described as being away from freedom and toward government tyranny.
Of the ten accused informants under this act, none were said to have spied for the Soviet Union, only one, Bradley Manning, allegedly leaked information that may have compromised the safety of American and allied military personnel and one, Jeffrey Sterling, allegedly leaked information about US planned sabotage of the Iranian nuclear program, which could have perhaps enabled the Iranians to develop a nuclear weapon somewhat earlier. These three could have arguably compromised our security.
The others, however, disclosed classified details, mostly to reporters, that in the Old America, We the people would have felt entitled to know.