In the United States v. Cores case of 1957, the Supreme Court ruled on issues related to labor law and maritime law. The defendant, a seaman named George Cores, was accused of inciting a mutiny aboard his ship while it was in international waters. He had encouraged his fellow crew members to strike for better working conditions and wages but did not use violence or threats thereof. The government argued that this constituted an act of revolt under federal laws against mutiny at sea. The Supreme Court disagreed with the government's interpretation and acquitted Cores of all charges. In their decision, they noted that peaceful strikes were protected activities under American labor laws even when conducted on board ships in international waters; thus these actions could not be considered as acts of rebellion or insurrection unless accompanied by violent behavior or clear intent to usurp authority from ship officers. This ruling clarified important aspects regarding workers' rights within maritime contexts and emphasized that non-violent protests for improved conditions are legal regardless if they occur domestically or internationally.

In the dissenting opinion for United States v. Cores, Justice Brennan argued that the majority's interpretation of Section 7 of Title II of the Immigration and Nationality Act was too broad. He contended that this section should only apply to those who knowingly provide transportation to illegal immigrants with an intent to violate immigration laws, not simply those who unknowingly transport them as part of their job duties. In his view, a ship’s crew member like Cores could not be held criminally liable unless he had specific knowledge about the immigrant's status and intentionally helped him evade authorities. The majority decision effectively made every seaman potentially guilty if they transported any passenger without thoroughly investigating their legal status - something beyond their professional responsibilities or capabilities.