The two men complained to the labor board [National Labor Relations Board], which last week lodged charges against their company, Consolidated Bus, accusing it of illegally spying on the men and threatening to assault them. The labor board said the company had illegally retaliated against Mr. Fleurimont and Mr. Guzman for trying to exercise their rights as union members in ways that displeased the company and their union, Teamsters Local 854.