In the 1940 case of Milk Wagon Drivers Union of Chicago, Local 753, et al. v. Meadowmoor Dairies, Inc., the U.S Supreme Court upheld an injunction against a union that had resorted to violence during a labor dispute with Meadowmoor Dairies in Chicago. The court ruled that while peaceful picketing was protected by the First Amendment right to free speech, this protection did not extend to violent or intimidating behavior used as part of industrial action. The decision affirmed that courts could issue injunctions against unions engaging in such conduct and held that it was within their power to maintain peace and protect property rights even if it meant limiting some forms of protest.

In the dissenting opinion for Milk Wagon Drivers Union of Chicago, Local 753 v. Meadowmoor Dairies, Inc., Justice Black argued that the majority's decision to uphold an injunction against a union's peaceful picketing was in violation of First Amendment rights. He contended that there was no clear and present danger posed by the union’s actions to justify such restrictions on free speech. The justice also disagreed with the majority’s view that previous violent acts associated with this labor dispute could taint all future activities by these workers as inherently dangerous or threatening. According to him, each case should be evaluated independently based on its own merits rather than past incidents related to it; otherwise it would lead towards punishing individuals not for their deeds but because they belong to a particular group which had been involved in violence before.