In Greene v. McElroy et al., the U.S. Supreme Court ruled in favor of an aeronautical engineer who had lost his security clearance without being given a chance to cross-examine those who provided adverse information about him, thus violating his due process rights under the Fifth Amendment. The court held that no explicit authority existed for denying Greene's right to confront and cross-examine witnesses against him during proceedings related to his security clearance revocation by the Department of Defense (DoD). The DoD argued it was acting on implied executive authority, but the court rejected this argument stating that such serious infringements on individual liberties could not be justified based solely on implications or vague inferences from statutory provisions or general grants of power.

In the dissenting opinion for Greene v. McElroy et al., Justice Clark argued that the majority's decision undermined national security by limiting the executive branch's authority to deny security clearances based on confidential information. He contended that this case was not about an individual’s constitutional rights, but rather about a privilege granted by Congress and regulated under its authority. He believed it was within Congress' power to delegate such decisions to administrative agencies without requiring them to provide full judicial-style hearings or allow cross-examination of witnesses in every case. Furthermore, he pointed out that there were other remedies available if someone felt they had been unfairly denied a clearance, including appealing directly to higher authorities within the agency or seeking redress through political channels.