In the 1940 case of Milk Wagon Drivers' Union, Local No. 753 et al. v. Lake Valley Farm Products, Inc., the U.S Supreme Court ruled in favor of Lake Valley Farm Products and other dairy companies who were defendants against a union representing milk wagon drivers in Chicago. The court held that peaceful picketing by labor unions could be restricted if it was part of a broader pattern of violent conduct or intimidation tactics aimed at achieving their objectives - which was found to be true in this case as there had been instances where violence and threats were used by the union members during strikes to coerce compliance from non-unionized workers and employers alike. This decision marked an important shift towards limiting certain rights associated with collective bargaining under federal law when they infringe upon public safety or order.

In the dissenting opinion for the Milk Wagon Drivers' Union, Local No. 753 v. Lake Valley Farm Products, Inc., Justice Black argued that the majority's decision to uphold an injunction against a labor union's peaceful picketing was inconsistent with previous Supreme Court rulings and violated First Amendment rights of free speech and assembly. He contended that this ruling would allow courts to interfere in labor disputes on behalf of employers, thereby undermining workers' ability to collectively bargain or protest unfair conditions. Furthermore, he criticized the court for not considering whether there were less restrictive means available before resorting to such a severe measure as an injunction. In his view, this case represented a dangerous expansion of judicial power into areas traditionally reserved for legislative action.