In Zittman v. McGrath, Attorney General, Successor to the Alien Property Custodian (1950), the U.S. Supreme Court was asked to decide whether or not property seized by the United States government during World War II could be returned to its original German owners after the war ended. The case involved a group of German citizens who had deposited money in an American bank before WWII and whose assets were subsequently frozen by the U.S Government under Trading with Enemy Act as they were considered "enemy-owned" properties. After Germany's surrender, these individuals sought return of their funds but faced opposition from Leo T. Crowley, then Alien Property Custodian appointed by President Franklin D Roosevelt. The court ruled that while it is within Congress' power to seize enemy-owned property during wartime for national security purposes; once peace has been restored such seizure becomes punitive rather than remedial and thus violates Fifth Amendment rights against taking private property without just compensation unless there is explicit Congressional intent stating otherwise which wasn't present here. Therefore, despite being initially classified as enemies due to their nationality during wartime; these individuals retained certain constitutional protections allowing them access back to their previously seized properties post-war.

In the dissenting opinion for Zittman v. McGrath, it was argued that the majority's decision to allow the U.S. government to seize property from German nationals during World War II under the Trading with Enemy Act violated principles of international law and justice. The dissenters believed that this act should only apply in cases where enemy aliens had a direct interest or were directly involved in hostile actions against America, not simply because they were citizens of an enemy nation. They also expressed concern over potential retaliation by other nations against American citizens abroad if such broad seizure powers were upheld as constitutional. Furthermore, they disagreed with how broadly "property" was defined by the court - including intangible assets like debts owed by Americans to Germans - arguing this interpretation went beyond what Congress intended when passing the legislation.