A prisoner prohibited from speaking to his family for four months after uttering the words “As-Salaam-Alaikum.” Books that have to be destroyed after one prisoner reads them, lest he somehow use the pages to pass along secret notes. Letters to family members that have to be copied and analyzed by intelligence officers before they are sent out, meaning they may take months and months to arrive.

These are the types of restrictions faced by a small number of prisoners locked up in the United States, including some people who have never been convicted of a crime The rules, called Special Administrative Measures, or SAMs, are the subject of a recently released report by the Center for Constitutional Rights and Yale Law School’s Allard K. Lowenstein’s International Human Rights Clinic. The study, an unusual undertaking, makes the case that SAMs violate both U.S. and international law, threaten basic constitutional protections, and may even constitute torture.

Just about 50 prisoners nationwide were subject to SAMs as of June this year, most of them Muslim. Prisoners who have previously been subject to this sort of detention describe the experience as like being in a world unto itself, in which they have no human contact with anyone other than their lawyers and very occasional, highly restricted communication with immediate family members. Many of those on SAMs have developed mental health issues as a result of the isolation, which may prevent them from contributing to their own defense. Moreover, people under SAMs are prohibited from contacting the media, and their attorneys and family members could be prosecuted for revealing anything the prisoner has said — meaning the highly restrictive world of SAMs is highly secretive, too.

“I wouldn’t be able to publicly repeat anything a SAMs client might have told me, whether about her health, her conditions, her treatment by guards, the weather, what she ate for lunch,” said Pardiss Kebriaei, a senior staff attorney at the Center for Constitutional Rights who has represented clients on SAMs in the past. “Every utterance is off limits, even if it is in no reasonable way linked to safety and security.”

Justice Department officials have claimed that SAMs are a crucial tool in the government’s national security arsenal, an assertion fiercely disputed by defense attorneys of terrorism suspects as well as human rights advocates. Among the most serious concerns raised in the CCR and Yale Law report is that the government uses SAMs to coerce accused terrorists into pleading guilty or sharing sensitive information.

“SAMs are the darkest corner of the U.S. federal prison system, combining the brutality and isolation of maximum-security units with additional restrictions that deny individuals almost any connection to the human world,” the report says. “Those restrictions include gag orders on prisoners, their family members, and their attorneys, effectively shielding this extreme use of government power from public view.”

In this Feb. 25, 2016, photo, correctional officer Lt. Joshua Macomber looks into a cell in what prison officials describe as a disciplinary confinement area rather than solitary confinement, at the Rhode Island Department of Corrections High Security Center, in Cranston, R.I.

Photo: Steven Senne/AP

Special Administrative Measures came into being in 1996, soon after the Oklahoma City bombing. The regulations grant the attorney general sole discretion to limit a prisoner’s communication if she determines that there is a “substantial risk” the prisoner’s contact with the people other than their lawyer or prison officials could pose a threat to the safety of people in the outside world. For example, someone might be placed on SAMs for fear that they would threaten a witness or communicate plans to execute a terrorist attack. Yet there are essentially no checks on the attorney general’s power to impose the onerous restrictions, nor evidentiary standards she is required to meet in order to do so. As the CCR and Yale Law report points out, “The attorney general’s justification often cites little more than the prisoner’s charges or conviction.”

People placed on SAMs are almost completely cut off from the world outside their cell walls. Whereas most prisoners in solitary confinement don’t face express prohibitions on communicating with each other and usually find ways to do so — for example, by shouting through air vents or sink drains — these creative avenues for human connection are prohibited and punishable offenses for prisoners under SAMs. These prisoners are barred from contacting anyone other than their attorneys and immediate family members, and even familial communications are strictly limited. Individuals may be limited to making one 15-minute phone call per month, and to sending out one, three-page, double-sided letter to a pre-cleared family member each week.

And whereas most prisoners know their letters and phone calls could be monitored, SAMs prisoners don’t even have the pretense of privacy, since the special measures actually mandate that all familial communication (and in some cases, legal contact) be surveilled and stored by the FBI. Since their phone calls must be contemporaneously monitored and recorded, SAMs prisoners are not even allowed to make calls to family members in languages other than English unless a government-approved translator is available.

In many cases, SAMs are imposed before a trial, but the CCR and Yale Law report also notes that some prisoners are subject to SAMs for years even after their conviction. One Muslim prisoner, Ahmed Abu-Ali, has been under SAMs continuously since 2005, and so has not been able to talk to any extended family members for over a decade, or anyone else in the outside world bar his parents and siblings. “When my grandfather became terminally ill in 2006, his dying wish was to talk to Ahmed, which we could not fulfill, due to SAMs,” his sister Mariam told the report’s authors.

Individuals in contact with a SAMs prisoner can and have been criminally prosecuted for repeating what the incarcerated individual has told them. In 2005, defense attorney Lynne Stewart was convicted of material support for terrorism and sentenced to decades in prison for passing on a client’s statement to the press, in violation of his SAMs. (She was granted “compassionate release” in January 2014 as a result of a terminal cancer diagnosis, and passed away in March 2017.)

Another prisoner, Ali Yasin Ahmed, was subject to SAMs before his trial for about three years, beginning in 2013. Locked up alone day after day, Ahmed even faced restrictions on one of the few avenues of escape available to him — books. When Ahmed was held on the SAMs unit at the Metropolitan Correctional Center in Manhattan, he and the other prisoners could never share books — meaning each time one of them finished reading something, it had to be destroyed. Ahmed also was banned from reading anything about anyone who has ever been in federal prison.

For Ahmed, such extreme conditions of isolation drove him to desperation. “I think that it may be hard for you, judge, to imagine how excited I feel when I know that a book is on its way,” Ahmed wrote in the 2015 letter he sent to the judge before his sentencing. “I wait and wait. I tell myself to be calm, soon there will be something to occupy my mind. But then the book is sent back and I am terrified by the mental quiet.”

According to the report, the number of prisoners subject to SAMs has increased significantly since the start of the war on terror; whereas in November 2001 there were only 16 individuals under SAMs, as of June 8, 2017, there were 51. While Muslims are not the only people placed under SAMs, they are primary targets of the measures. “It appears that a major criterion for deciding whom to place under SAMs was not the prisoner’s demonstrated capacity to communicate dangerous information, but rather the prisoner’s religion,” CCR’s and Yale Law’s report says.

The regulations also grew stricter after 9/11, with the Justice Department introducing provisions that permit prison officials to monitor communication between prisoners and their attorneys, and expressly allow prisoners to be placed on SAMs before their trials.

A U.N. official has said SAMs could very well violate international law. In 2012, Juan Méndez, then the U.N. special rapporteur on torture, was asked about the British government’s plan to extradite a number of terrorism suspects to the U.S. “I think there [are] very good arguments that solitary confinement and SAMs would constitute torture and prevent the U.K. from extraditing these men,” he told The Independent.

Some defense teams who have worked with SAMs prisoners say the measures are designed to be coercive. Sean Maher, an attorney who has represented several terrorism suspects on SAMs, told Yale Law students that the restrictions are “meant to bludgeon people into cooperating with the government, accepting a plea, or breaking their spirit.”

In several instances, SAMs are dropped after a prisoner has pled guilty. The was the case for Ali Yasin Ahmed: The Justice Department did not renew their request for SAMs after he plead guilty to charges of material support for a terror group. Following the plea, he was transferred directly to a medium security prison — raising questions about whether the government actually believed he posed a national security threat as they had previously claimed.

Lawyers who have represented clients on SAMs say the extreme conditions of isolation undermine their ability to establish a relationship of trust, and hinder their clients’ ability to contribute to their own defense. Joshua Dratel, who has represented a number of high-profile terrorism suspects in both U.S. civilian courts and in Guantánamo, told the report’s authors that SAMs “dehumanize defendants and create a situation where they cannot exist in a defiant posture [to] fight the case,” which “eliminate[s] them as participants in their defense.”

Despite the immense impact that SAMs can have on a prisoner’s life, there are few procedural protections in place for incarcerated people to contest the measures. Prisoners cannot challenge a SAM designation until after they have been placed under the measures. “Even when prisoners can bring challenges, courts routinely rule against them, accepting the government’s vague national security justifications,” says CCR and Yale Law’s report.

“Basically, we now have built into our legal system a way for the government to inflict what the international community has deemed torture pretrial with almost no recourse to challenge,” said Jeanne Theoharis, a professor of political science at Brooklyn College who has written extensively on civil liberties issues related to terrorism prosecutions, including the pretrial imposition of SAMs.

Such measures, Theoharis said, allow the government “to alter and tip the adversarial process built into our legal system — which Americans count on to prevent abuses — drastically to their favor.”

Lynne Stewart, center, is surrounded by supporters and reporters in New York after a federal appeals court in New York City said a judge who sentenced Stewart to just over two years in prison should consider a harsher sentence in light of her case’s terrorism connection.

Photo: Mary Altaffer/AP

SAMs also prevent journalists from testing the government’s account of alleged crimes, or to investigate claims of prisoner abuse. When investigative reporter Bryan Denson was working on a book about CIA officer-turned spy Jim Nicholson, Denson was never able to interview Nicholson, due to SAMs. Asked if he thought SAMs constrained public debate when it comes to national security issues, Denson told The Intercept, “It would have to, if you’re unable to reach the source of the very national security issue you’re trying to write about.”

The CCR and Yale Law report highlighted the case of one prisoner, Mahdi Hashi, a British prisoner of Somali origin who reportedly went on hunger strike in 2013 to protest his conditions. As the Intercept has reported, journalists were unable corroborate this information because the only people who would know – Hashi, his attorney, and his family – were all subject to SAMs.

“SAMs are a form of torture,” Kebriaei, the CCR attorney, told The Intercept. “But SAMs gag the person tortured — the prisoner — from speaking. That’s one of the issues we raise in the report: not just what SAMs do to the prisoner living under them, but the way they shield the effects from public knowledge.”

These strict measures have now been in existence for over 20 years. And while they certainly continued to be instated and enforced under President Barack Obama’s Department of Justice, defense attorneys and civil liberties advocates are worried that under President Donald Trump, things will only get worse.

“Advocates on both sides of the aisle have criticized President Trump for vowing to ‘bring back torture,’ but the torture of SAMs and indefinite solitary confinement never went away,” said Allison Frankel, one of the student authors of the report, in a statement. “Right now, the only thing protecting prisoners from being placed under SAMs is the discretion of Attorney General Jeff Sessions.”

Update: November 1, 2017 This article was updated to clarify that Yale Law students did the interviews and authored the report, which was then published jointly with Center for Constitutional Rights.