Critics reacted with horror to a Monday report from The Associated Press detailing how US Immigration and Customs Enforcement has abruptly ended its practice of disclosing the locations of thousands of detainees.

According to the AP, ICE "has stopped publicly revealing where it is holding... detainees who are subject to final deportation orders, an unannounced move that has made it far more difficult for lawyers and relatives to find them."

Immigration attorneys who spoke with the AP said that their clients had "vanished" from the system after ICE removed them from its online detainee locator system last week.

Greg Chen, senior director of government relations at the American Immigration Lawyers Association, told the AP that families of detainees "are freaking out because they think the person has been deported and they don't know where the person might be."

Chen added that the new policy has "serious implications" for attorneys' ability to make contact with their clients.

Michelle Mendez, legal director at the National Immigration Project, told the AP that the new policy is "just another iteration of disappearing people."

"Why would we do that in the United States of America?" Mendez asked. "It's something we'd hear about in another country and be concerned about individual rights and due process."

Tom Jawetz, senior fellow at the Center for American Progress, echoed Mendez's analysis, writing in a social media post that the AP report reveals "an official government policy of disappearing people," as "systems for attorneys and loved ones to know where—even whether—a person with a final removal order is in ICE custody have been wiped clean."

Aaron Reichlin-Melnick, senior fellow at the American Immigration Council, described the new ICE policy as "unprecedented" for US immigration enforcement.

"People who have been detained for months are suddenly disappearing from the locator system—even if they haven't been moved anywhere," Reichlin-Melnick explained. "And people newly arrested are not showing up at all, their location now hidden from view."

Georgetown University political scientist Jonathan Ladd argued that the ICE policy was a fundamental violation of long-established rights in the US that date to before the country's official founding.

"The government moving or hiding jailed people to avoid review by courts isn't some loophole in our habeas corpus rights," Ladd explained. "This government behavior has been considered a violation of the people's habeas corpus rights since at least the Habeas Corpus Act of 1679."

Ladd further pointed out that "habeas corpus rights are guaranteed by Article I of our Constitution," which means "hiding prisoners from the courts is unconstitutional."