The Miller v. California case, decided in 1973, was a landmark decision by the United States Supreme Court that redefined its definition of obscenity from that of "utterly without socially redeeming value" to that which lacks "serious literary, artistic, political or scientific value." The case began when Marvin Miller conducted a mass mailing campaign to advertise the sale of adult material and was subsequently convicted under a California statute for distributing obscene materials. In his appeal before the Supreme Court, he argued this law violated his First Amendment rights. However, the court ruled against him in a 5-4 decision stating not all speech is protected by the First Amendment and created what became known as 'the Miller test' for determining whether speech or expression can be labeled obscene and thus lose its protection under the first amendment: (1) if 'the average person applying contemporary community standards' would find that it appeals to prurient interest; (2) depicts sexual conduct specifically defined by applicable state law; and (3) lacks serious literary, artistic etc., value.

In the dissenting opinion for Miller v. California, Justice William O. Douglas argued that the First Amendment should protect all forms of expression unless they cause a direct and immediate harm to society. He believed that obscenity laws were too vague and subjective, leading to arbitrary enforcement based on personal tastes or moral views rather than objective standards. Furthermore, he contended that it was not within the government's purview to regulate morality or taste in art and literature; such decisions should be left up to individual citizens themselves. In his view, any form of censorship posed a threat to freedom of speech and thought as protected by the Constitution.