The sudden exposure of labor spies has driven workers "to violence and unreason", including at least one shooting war.
Both the spy agencies and the companies that employ labor spies prefer to keep their activities secret.
The same agencies that provide labor spies often provide guards who act in concert with the intelligence services.
In 1919-1920, a religious commission investigating labor spies was itself the target of labor spying.
The employers planted a labor spy in the union, and 42 union members were fired.
The Committee reported that as late as 1937, its census of working labor spies from 1933 to 1937 totaled 3,871 for the period.
Membership in the union was kept secret, for fear of labor spies and physical retaliation.
By the 1930s, agencies began to rely more upon the use of informants and labor spies.
The company feared the unionization attempt and hired labor spies to follow the union leaders and determine their plans.
Some corporations have sought to learn of union activities by employing informants, labor spies, and saboteurs.
