Last week, the N.C. Department of Public Safety announced it would immediately remove The New Jim Crow: Mass Incarceration in the Age of Colorblindness from its list of publications that are banned in state prisons and review whether any other publications should be removed from the list. The move came a day after the ACLU of North Carolina sent DPS officials a letter demanding they do so.

Prohibiting Michelle Alexander’s award-winning 2010 book is not only a violation of prisoners’ First Amendment rights, the ACLU said, but also “cruelly ironic given the critical role it plays to understanding the pervasive racial injustice behind our epidemic of mass incarceration.”

North Carolina isn’t the only state where the book has been banned in prison. Earlier this month, under fire from that state’s ACLU chapter, New Jersey prisons lifted their ban on the book. It’s also banned in Florida.

DPS policy lets a facility prohibit an inmate from receiving a publication for a range of reasons that largely fall under the umbrella of disrupting “institutional order, security and safety” and “inmate rehabilitation.” Sexually explicit material (Booty! Pirate Queens Volume 1 is prohibited in N.C. prisons) as well as publications depicting violence (A Game of Thrones Volume 1) or insurrection (The Anti-Government Movement Guidebook) can be banned. How-to information on manufacturing weapons, drugs. or poisons, disabling communication or security systems, or escaping from confinement may also be grounds for prohibition. Large, hardcover books may also be banned (Encyclopedia of North Carolina), with an exception made for legal and religious publications.

However, according to policy, “no publication or material will be withheld solely on the basis of its appeal to a particular ethnic, racial or religious group. A publication may not be rejected solely because its content is religious, philosophical, political, social or sexual, or because its content is unpopular or repugnant.”

The most recent Disapproved Publications Report includes 480 titles prohibited in the past twelve months. Among the more unusual inclusions: Maya Angelou’s I Know Why the Caged Bird Sings, because it features the rape of a minor; Prison Ramen, a book of ramen recipes devised by inmate-cooks that apparently includes instructions on how to stow a razor blade; HopeA Memoir of Survival in Cleveland, written by the two women who in 2013 famously escaped ten years of captivity in a Cleveland man’s home; and the May 2017 edition of Elle Décor and the October 2017 issue of O: The Oprah Magazine, for reasons unknown.