From the CS. Lewis Society:
Religious Books Banned in Federal Prison
In the name of "fighting terrorism," federal Bureau of Prisons bureaucrats are banning any religious books in prisons not on the Bureau's short, restricted list of approved books. Among the books banned are ones by C. S. Lewis, Rick Warren, Paul Tillich, Karl Barth, Moses Maimonides, Charles Schuller, Harold Kushner, and many, many other authors. The wholesale censorship has ordered federal prison chaplains to comply based on the premise that library materials should be "free of discrimination, disparagement, advocacy of violence and religious radicalization." The purge resulted from a 2004 report by the Office of the Inspector General in the Justice Department that recommended that prisons take steps to avoid becoming recruiting grounds for militant Islamic and other religious groups, the New York Times reported.
New York Times
A class action suit has been filed by two prisoners in upstate New York, one a Christian and the other an Orthodox Jew.Needless to say, C.S. Lewis was a very strong opponent of literary censorship, as he discussed in a number of his books, including PRESENT CONCERNS.