The U.S. Supreme Court case Pattern Makers' League of North America, AFL-CIO v. National Labor Relations Board (1984) revolved around the issue of whether a union's imposition and enforcement of fines on members who crossed picket lines during a strike violated the National Labor Relations Act (NLRA). The court held that such actions by unions did indeed violate Section 7 of NLRA, which guarantees employees "the right to refrain from any or all" concerted activities for collective bargaining or other mutual aid or protection. This decision was based on an interpretation that this section not only protects employees’ rights to engage in collective action but also their rights to abstain from it when they choose so without facing penalties imposed by their own union.

In the dissenting opinion for Pattern Makers' League of North America, AFL-CIO v. National Labor Relations Board, Justice Blackmun argued that the majority's decision was a departure from established labor law principles and precedent. He contended that it undermined collective bargaining by allowing individual members to break away from their union during a strike action without facing any consequences or penalties imposed by the union itself. According to him, this could potentially weaken unions and disrupt industrial peace as it would encourage disunity among workers in times of conflict with employers. Furthermore, he expressed concern over how such an interpretation might be applied inconsistently across different cases due to its subjective nature - what constitutes "reasonable" fines or penalties may vary greatly depending on one's perspective.