The Marysville School District has, at least temporarily, banned PG-13 and R rated movies from the school's curriculum. The ban is the result of complaints by parents that such films contain too mature of a content for high school students. Thus, historical films like "Schindler's List" and "Saving Private Ryan" will now be off limits to students within that district.
Generally, courts uphold the right of boards of education to make decisions like which course materials to use against the constitutional claims of students and teachers alike. However, the case may be different if these materials are held in the library where students may access them, and are being removed "simply because they dislike the ideas contained in those books and seek by their removal to 'prescribe what shall be orthodox in politics, nationalism, religion, and other matters of opinion.'"
However, showing the films in a classroom (as opposed to private student viewing) may be more likely to bear the school's 'imprimatur' and probably can, consistent with the First Amendment, be banned pursuant to school board policy. See e.g. Hazelwood v. Kuhlmeier, 484 U.S. 260.