Civil Liberties: Should Prison Inmates Reading Rights be able to be Restricted?

Restricting prison inmate's access to certain reading materials is probably considered reasonable by most but is it reasonable to restrict all access to all reading material with the only exclusion being the Bible?

A 16 page complaint by the American Civil Liberties Union pointed out that prison officials in South Carolina had done this and as a result were violating the inmates constitutional rights of free speech, freedom of religion and right to due process. Inmates were not allowed newspapers, magazines, or any other kind of book and the jail did not have a library.

As has been said on this matter prison is not just about punishment - "It's easy to forget that rehabilitation is an essential part of any functional criminal justice system and that rehabilitation at its core means self-sufficiency. Assisting inmates in finding employment and securing health care enables that kind of self-sufficiency and works towards the common goal of keeping citizens out of jail.  It's not a hand-out nor is it "rewarding" inmates for prior bad behavior. It's just common sense."

Do you think the "Bibles only" policy is a fair punishment? Are the civil libertarians right to challenge the prison authorities?