Back in March, the Motion Picture Association of America re-launched its film-rating website, filmratings.com. While this may be old news to some, I just learned about it from a post on BoingBoing which makes fun of the rationales given for the ratings, which are available on the new website. Example: The movie "3 Ninjas Knuckle Up" was "rated PG-13 for non-stop ninja action."
It's fine to joke about particular ratings, but we shouldn't forget that the MPAA's rating system was created to avoid government censorship, which was a real possibility after the 1915 U.S. Supreme Court case Mutual Film Corporation v. Industrial Commission of Ohio, which ruled that "the exhibition of moving pictures is a business, pure and simple, originated and conducted for profit ... not to be regarded, nor intended to be regarded by the Ohio Constitution, we think, as part of the press of the country, or as organs of public opinion." By a unanimous vote, the Supreme Court ruled that the First Amendment did not apply to motion pictures because "they may be used for evil." (There was also an issue of whether the First Amendment applied to state actions, but because the state constitution at issue was substantially similar to the U.S. Constitution, that was not a factor in the opinion).
After a number of Hollywood scandals and public outcry over the immorality of Hollywood in the 1920s, the Motion Pictures Producers and Distributors Association (the precursor to the MPAA), adopted the Motion Pictures Production Code (known as the "Hays Code" after the first MPAA president) in 1930. The code required that "No picture shall be produced that will lower the moral standards of those who see it. Hence the sympathy of the audience should never be thrown to the side of crime, wrongdoing, evil or sin."
This self-regulation led to the dissolution of many state and city censorship boards.
The 1952 case Joseph Burstyn, Inc v. Wilson directly overturned the earlier decision, but by that time the Hays Code was already well-established.
Under the Code, films were simply approved or disapproved based on whether they were considered "moral" or "immoral." Two years after Jack Valenti became president of the MPAA in 1966, he replaced the Hays Code with what is essentially the rating system we have today.
Our current system is far from perfect. Kirby Dick made a whole movie about how he believes the current system is too focused on sexuality and not focused enough on violence and that it gives harsher ratings to independent films and films dealing with homosexual issues. But the beauty of the system is that theaters are free to show movies that have not been rated by the MPAA, consumers are free to buy such movies and watch them at home, and other groups (e.g. parent and religious groups) are free to provide their own ratings--and they do.
In summary, the MPAA's ratings may sometimes be off the mark, but what would really be silly is suggesting that they stop rating films or that the government take over.