Also try searching CQ Researcher for background information. Here are their guides for Communication and the Mass Media: Regulation and Legal issues
Sample searches (in EBSCO databases) by Subject:
Suggested library databases:
Also search Nexis Uni for current news and law review articles:
SSRN may have some law review pre-prints:
Click on one of these subjects from out catalog to find books, ebooks and videos:
Also try a keyword search for banned OR censored.