Jacobellis v. Ohio

Justice Stewart's notion of knowing obscenity when he saw it has been quoted in more than 150 court decisions. Eventually, Stewart's frustration with the general inability to define obscenity led him to join Justice Brennan in the belief that obscene material should not be suppressed, because of the difficulty of suppressing only it and not permissible material as well. By 1973, Justices Stewart, Brennan, and Marshall were all arguing that the state should regulate only the distribution of obscene material to children and unconsenting adults, leaving consenting adults to enjoy obscene material if they chose.