The U.S. Supreme Court case El Vocero de Puerto Rico (Caribbean International News Corp.) v. Puerto Rico, et al., 1992 dealt with the issue of freedom of press and prior restraint in relation to court proceedings. The plaintiffs, a newspaper company and its reporters, challenged a law in Puerto Rico that prohibited the media from publishing information about certain criminal cases before trial without permission from the court. They argued this was unconstitutional as it violated their First Amendment rights by imposing an unlawful prior restraint on speech. The defendants were officials from Puerto Rico who defended the law's constitutionality arguing it protected defendants' right to fair trials by preventing prejudicial pretrial publicity which could influence potential jurors negatively against them. However, after reviewing previous precedents related to similar issues such as Nebraska Press Association v Stuart (1976), where restrictions on media coverage were deemed unconstitutional unless they met strict criteria proving necessity for maintaining justice; and Sheppard v Maxwell (1966) where courts are required to consider other measures like change of venue or jury sequestration before resorting to restraining orders against press; the Supreme Court ruled in favor of El Vocero de Puerto Rico stating that any attempt at restricting free speech must meet rigorous standards which weren't satisfied here thereby declaring said law unconstitutional.

In the dissenting opinion for El Vocero de Puerto Rico v. Puerto Rico, it was argued that the majority's decision to uphold a law restricting media access to preliminary criminal proceedings violated First Amendment rights. The dissenters believed that such restrictions were not narrowly tailored enough to serve compelling state interests and thus failed strict scrutiny, which is typically applied in cases involving fundamental constitutional rights like freedom of press. They also contended that there was insufficient evidence demonstrating these restrictions effectively protected defendants' right to fair trial or safeguarded against prejudicial pretrial publicity as claimed by proponents of the law. Furthermore, they expressed concern about potential chilling effects on free speech and press due their broad interpretation of what constitutes "preliminary proceedings".