Amazing how much social, political, and religious baggage and weirdness has been heaped on the movies over the past century.  From fairly early on, the governmental and religious keepers of public morals have been attempting to ban,  cut, or otherwise limit access to films perceived to be threats to society.  To get an idea of the startling range of films that have historically fallen under the censors' ax, check out MRC's new Banned Films videography at:

http://www.lib.berkeley.edu/MRC/bannedfilms.html

For a bibliography of books and articles about movie censorship, see:

http://www.lib.berkeley.edu/MRC/censorship.html