-The movie ratings are a voluntary industry policy, -not state action. Which is all the difference in the -world, as you know. It means that you can't challenge -the ratings policy under the First Amendment.
The legal basis may be different it's true, but the R-ratings exist under the original threat of government regulation in the abcense of industry self-regulation. So as far as empirical history, there is little difference as far as their fascist nature.
And given the recent decisions on library filters, it's quite clear that the Court will uphold state restrictions on access to information by minors as long as adults have the clear ability to access that same information.
-- Nathan