Immigration and Customs Enforcement (ICE) is removing the names of its detainees who are facing final deportation orders from its public online database.

The move will disrupt detainees’ legal challenges to deportation and leave their whereabouts unknown to their lawyers and loved ones.

The agency quietly removed thousands of people from its online detainee locator on September 15, the Associated Press reports. Certain detention facilities will not be subject to the new order if judges have ruled that they are required to list detainees in their facilities.

The exact number of names removed is unclear, but judges have issued over 740,000 removal and voluntary departure orders this year, while reports have found that ICE arrested nearly 16,000 people in July who were subject to final removal orders. Experts and advocates have criticized the practice as digitally “disappearing” immigrants, saying that it’s yet another erosion of due process rights.

The agency has also issued a new policy barring immigration officials from sharing the locations of such detainees, two former Department of Homeland Security officials told The Washington Post.