The U.S. Supreme Court case Byrne, District Attorney of Suffolk County, et al. v. Karalexis et al., 1970 revolved around the issue of obscenity and freedom of speech under the First Amendment rights. The respondents owned a movie theatre in Massachusetts where they exhibited an allegedly obscene film "I am Curious (Yellow)". They were charged with violating state laws prohibiting the exhibition of obscene material and sought to have these charges dismissed on grounds that these laws violated their constitutional rights to free speech and due process as per the First Amendment and Fourteenth Amendment respectively. However, the Supreme Court upheld their conviction stating that it was not unconstitutional for states to prohibit showing obscene films even if they did not incite violence or any criminal activity.

In the dissenting opinion for Byrne, District Attorney of Suffolk County, et al. v. Karalexis et al., Justice Hugo Black disagreed with the majority's decision to remand the case back to state court without making a definitive ruling on whether or not Massachusetts' obscenity law was constitutional. He argued that by doing so, they were avoiding their responsibility as Supreme Court justices and leaving it up to lower courts to interpret what is considered obscene content under federal law. Furthermore, he believed that this approach could lead to inconsistent rulings across different jurisdictions and potentially violate individuals' First Amendment rights due to varying interpretations of what constitutes obscenity. In his view, any form of censorship infringes upon these rights and should be deemed unconstitutional regardless of its nature or context.