Ever since the 1960s, when the Motion Picture Association of America under director Jack Valenti first established the system of labeling movies according to age and suitability for specific audiences, filmmakers and critics alike have criticized the rating system as ineffective, inaccurate and often meaningless. The MPAA's Classification and Rating System was initially restricted to a four-tier system of G (general audience, suitable for children); PG (parental guidance for children suggested); R (restricted to adults, usually defined as anyone over 18); and X (explicitly and graphically sexual in a manner likely to offend those opposed to pornography). The problem lay mostly with the X rating, which came to be outdated with the introduction of increasingly graphic sex scenes in otherwise mainstream, non-pornographic movies. Directors and producers complained that studios and backers were reluctant to finance film projects likely to earn an X rating for perhaps a single explicit sex scene, and argued that their scripts were in effect being "self-censored" by the inability (or unwillingness) of most filmmakers to forego financial backing and wide distribution for the sake of artistic freedom.
             The question was not fundamentally one of obscenity laws, which represent a distinct but rapidly shifting area of American law. Such laws have generally not been applied to motion pictures since the groundbreaking distribution of the Swedish film I Am Curious, Yellow, a mildly erotic film of the 1960s which is strikingly tame by today's standards. As a matter of practical fact, notes a recent Economist article,
             America has no censorship laws, and nobody can easily stop a cinema owner from showing any film he chooses, although most adhere to the system. The problem is what an X rating implies to the public. Most Americans assume it means that the film is pornographic; the ratings were not copyrighted when introduc...