In the case of Ioannou v. New York et al., 1962, the U.S Supreme Court dealt with issues concerning due process rights and self-incrimination. The petitioner, Ioannou, was a licensed plumber who had been summoned by a grand jury in an investigation into corruption within his industry. He refused to answer certain questions on the grounds that they might incriminate him. As a result, he was held in contempt of court and subsequently lost his plumbing license without any hearing or opportunity to defend himself before the licensing board as per state law at that time which allowed automatic revocation for refusing to testify before any legislative committee or judicial proceeding about matters related to their profession. The Supreme Court ruled in favor of Ioannou stating that this penalty violated his Fifth Amendment right against self-incrimination because it punished him for exercising this constitutional protection. Furthermore, it also violated his Fourteenth Amendment right to due process since he wasn't given an opportunity for hearing prior losing his professional license.

In the dissenting opinion for Ioannou v. New York, Justice Douglas argued that the majority's decision to uphold a state law requiring compulsory fingerprinting as part of an application for a driver's license was unconstitutional. He contended that this requirement violated the Fourth Amendment protection against unreasonable searches and seizures, as it forced individuals to provide evidence which could potentially be used against them in criminal proceedings without any suspicion of wrongdoing or probable cause. Furthermore, he suggested that such laws were indicative of a police state rather than a free society and warned about potential abuses if governments were allowed to collect personal information from citizens under compulsion without specific justification or safeguards in place.