In the 1964 case National Labor Relations Board v. Brown et al., DBA Brown Food Store, et al., the U.S. Supreme Court ruled that an employer's right to free speech was not violated by a National Labor Relations Board (NLRB) order prohibiting anti-union activities. The NLRB had found that Brown Food Store in Texas had engaged in unfair labor practices by distributing anti-union literature and making threats of reprisal against employees who supported unionization efforts, thereby violating Section 8(a)(1) of the National Labor Relations Act which prohibits employers from interfering with, restraining or coercing employees exercising their rights under this law. The Supreme Court upheld this decision on appeal, stating that while employers have a First Amendment right to express views about unions, they do not have an absolute right to engage in conduct aimed at preventing union organization if it infringes upon workers' rights protected under federal labor laws.

In the dissenting opinion for the case of NATIONAL LABOR RELATIONS BOARD v. BROWN et al., DBA BROWN FOOD STORE, Justice Harlan argued that the majority's decision was a departure from established principles governing labor disputes. He contended that an employer should not be forced to reinstate employees who had engaged in a "sitdown strike" - essentially seizing control of their workplace without permission - as this constituted illegal activity under both state and federal law. In his view, such behavior went beyond legitimate union activities protected by the National Labor Relations Act (NLRA). Furthermore, he disagreed with the majority's interpretation of NLRA provisions regarding unfair labor practices and remedies available to aggrieved parties. According to Justice Harlan, these provisions did not mandate automatic reinstatement but allowed for discretion based on individual circumstances.