From 1936 to 1937, the La Follette Committee began its assessment of four prominent anti-union practices which suppressed the advancement of organized laborers. The committee's intentions lay in preserving the rights of the worker when denied by employers, and in 1937, found industrial espionage to be a common tool employed against unions. From "motion-picture producers to steel makers," the enormous number of companies resorting to espionage, reported the La Follette Committee, prevented the practice of collective bargaining between companies and employees. Spies of corporations befriended victims into creating reports which they used to forewarn employers of potential strikes and assemblies. Spying, the La Follette Committee declared, weakens unions and "incites to violence, preaches strikes, inflames the hot-headed and leads the union to disaster". Detective agencies and those utilizing industrial espionage resorted to the protection against radicalism, exposure of theft, deterrence of sabotage, and improvement of labor-management relations as justification of their actions. The Federal Union of Automobile Workers, consisting of 26,000 members in the General Motors plant in 1934, was reported as having at least several spies in the union's executive board. Within two years, membership of the union dropped to merely 120. The Committee affirmed that through the employment of espionage, employees became subjugated to private corporations and were denied constitutional rights.