In Blount v. Rizzi, the U.S. Supreme Court ruled on a case involving the constitutionality of a federal statute that allowed postal authorities to stop mail they deemed "obscene." The plaintiff, Rizzi, operated an adult bookstore and had his mail stopped by Postmaster General Blount under this law. The court found in favor of Rizzi, ruling that the statute was unconstitutional because it violated due process rights as it did not provide for judicial review before stopping potentially obscene material from being delivered through mail services. This decision emphasized the importance of due process protections even when dealing with controversial materials like obscenity.

In the case of Blount, Postmaster General, et al. v. Rizzi, DBA The Mail Box (1970), there was no dissenting opinion recorded by any justice. All justices concurred with the majority decision that found in favor of Rizzi and ruled against the Postmaster General's attempt to stop mail delivery to a business selling allegedly obscene material without first obtaining a judicial determination on whether or not such materials were indeed obscene. This unanimous ruling emphasized due process rights under Fifth Amendment protections and highlighted potential First Amendment infringements if government officials could unilaterally determine what constitutes obscenity without court involvement.