AMARILLO, Texas — Texas is censoring prison mail in an attempt to stop the nationwide prison strike that has enveloped detention centers across the country.

The strike is against the “slave labor” guaranteed by the Thirteenth Amendment. The demonstration began in early September to mark the anniversary of the iconic Attica prison riot.

There was an initial bevy of interviews with prisoners across the country, explaining their positions. Then, not much.

Jerry Stein knows why.

Stein is a retired priest who has been writing prisoners for over 40 years. Back in May, an inmate serving time near Houston requested information on a prison strike taking place in California. Stein sent a news article about the strike to his incarcerated pen pal.

Then he received a notice showing that his mail was intercepted and destroyed. By the Texas Department of Criminal Justice, in an attempt to preempt the strike.

The mail was intercepted and destroyed because it “advocates work stoppage within TDCJ,” according to a document Stein provided to The Daily Beast.

“I was very careful to include only news clippings. It wasn’t instructions on how to strike,” Stein explained, saying he felt the letter’s destruction was a bit much.

“In a certain sense it would encourage work stoppage, but only in the sense that it might seem like the right thing to do,” he said. “It’s the first time I’ve ever seen anything like it.”

What worries him, as both a former priest and a concerned citizen, is what he views as a “blackout” on human rights for those in the criminal justice system.

He’s not the only one complaining. In Texas, two prominent members of the New Afrikan Black Panther Party-Prison Chapter (NABPPPC), a leftist organization inside prisons that teaches inmates about the law, politics, labor movements and history, have complained of censorship and other punitive measures for their involvement in the strike.

Keith “Malik” Washington, an NABPPPC spokesperson housed at a prison in New Boston, Texas, has repeatedly written of social media bans, denial of media visits, reading of privileged media mail and even solitary confinement for his efforts to recruit new prisoners to the strike.

Kevin “Rashid” Johnson, housed in the Clements Unit near Amarillo, Texas, has said the same. On his website, Johnson said that officials were “illegally opening and reading privileged legal and media mail … obviously focused on discovering, scrutinizing, and blocking any information coming into the prison about the work stoppage/strike planned for prisons across the U.S.” Texas and Florida are the only two states to guarantee privileged media mail for inmates.

The Daily Beast requested a media interview with Johnson to discuss these matters. The request was denied.

Jason Clark, TDCJ director of public information, explained that they “will not process interview requests for those who are actively recruiting other incarcerated persons to cause a work stoppage which could disrupt the safety and security of the unit and cause serious operational problems.”

It seems prisoner labor is very important.

Paul Wright, the editor of the Prison Legal News (PLN) told The Daily Beast that inmate labor is integral to all prisons across the U.S.

“Every single prison system relies on slave labor for the mundane things,” Wright began.

While many focus on the private corporations using labor inside prisons to produce goods—including Whole Foods, Walmart, Victoria Secret and many others—this is only a small part of the picture.

“Everything being done in the prisons—janitors, cooks, laundry workers—if prisoners weren’t doing that, they’d have to hire someone to do it and they’d have to be paying them at least minimum wage,” Wright explained. “It wouldn’t be possible, economically.”

Wright has intimate knowledge of U.S. prisons. He served 17 years for murder in a Washington state prison. In 1990, he began PLN behind bars.

The publication is sent out to prisoners across the country. It serves as a source of news concerning prison law and advocates for human rights protections for the incarcerated. It also challenges censorship of prison mail in courts across the country.

When asked what rights to expression and union organizing prisoners have, Wright succinctly replied: “None.”

Andrea Armstrong, a professor at the Loyola University Law School in New Orleans that focuses on the study of prisoners’ right to protest and how that intersects with race, told The Daily Beast that the legal decisions surrounding the issue are peculiar.

The decision from the 1966 case Adderley v. Florida concerned civil rights activists protesting outside against segregated facilities such as jails, movie theaters, police brutality and the arrest of fellow civil rights activists.

“The civil rights movement was deliberately getting arrested and they were deliberately protesting in jails,” Armstrong said. “There were supporters on the outside of the jail demonstrating with them.” These included Harriet Louise Adderley and a group of roughly 200 more.

The protesters ignored orders to leave the jail, leading to their arrest. They were charged with “trespass with a malicious and mischievous intent,” which they appealed all the way to the Supreme Court.

They lost. Their convictions were upheld and prisons were deemed non-public forums devoid of free speech. The decision has been used as a precedent in the years since to stop prison protests both inside and out.

The other is Jones v. North Carolina Prisoners’ Labor Union, decided in 1977. If you couldn’t tell from the name, this is the decision that decided inmates don’t have the right to join labor unions.

The North Carolina Prisoners’ Labor Union (NCPLU) grew out of the Black Power movement. It aimed to improve conditions and address grievances of inmates.

The North Carolina Department of Corrections prohibited soliciting other inmates to join the union, prohibited meetings, and restricted bulk mailings related to the NCPLU. A lower trial court ruled it was an infringement of the First Amendment, but the Court employed Adderley and a related decision to do away with that idea.

“These two cases greatly limit prisoners’ ability to protest inside facilities,” Armstrong said.

Beyond that, the Loyola law professor examines what happens if prisoners do decide to protest or organizes in spite of these limits.

“Correction officers and prison officials have an amazing amount of discretion when it comes to how to deal with protests,” Armstrong said.

These include a variety of “attitudinal charges” that have vague parameters, such as insubordination. Armstrong gave the example of being accused of inciting a riot inside a correctional facility, even when the “riot” is a nonviolent protest.

When asked for her view on how free labor inside prisons and lack of freedom of expression affect the country at large, Armstrong concluded: “We are creating, in many ways, a subordinate class. One of them is through labor, another is through repressing freedom of speech and critical thought. Those are two things, I think, that are essential to human dignity.”