In the case of United States et al. v. Euge, 1979, the U.S Supreme Court ruled on whether compulsory blood tests for alcohol content violated an individual's Fourth Amendment rights against unreasonable searches and seizures. The respondent, Euge, was a driver involved in a fatal car accident who refused to submit to a blood test at the hospital where he was treated for his injuries. The government argued that it had probable cause to believe that Euge had been driving while intoxicated and sought to compel him to undergo testing under Oregon’s implied consent law. The court held that such compelled intrusions into the body for blood are not within the scope of "searches" protected by the Fourth Amendment unless they breach an individual's dignitary interests in personal privacy and bodily integrity - which is determined based on societal expectations and norms rather than purely on subjective considerations or fears about potential misuse of extracted samples. Therefore, as long as there is reasonable belief (probable cause) of intoxication backed by clear evidence like erratic driving behavior or smell of alcohol etc., mandatory blood tests do not violate constitutional protections against unreasonable search/seizure.

In the dissenting opinion for United States v. Euge, Justice Stevens argued that the majority's decision to uphold compulsory blood testing as not violating the Fourth Amendment was flawed. He contended that such a test should be considered a "search" under constitutional law and thus subject to its protections against unreasonable searches and seizures. In his view, this interpretation would better align with past precedent where similar physical intrusions were deemed unconstitutional without proper consent or warrant. Furthermore, he expressed concern over potential abuses of power by authorities if they could compel individuals to undergo invasive procedures like blood tests without sufficient legal safeguards in place. He also disagreed with the majority's assertion that obtaining physical evidence from an individual does not infringe upon their Fifth Amendment rights against self-incrimination since it involves compelling them to provide potentially incriminating evidence about themselves.