WASHINGTON (AP) — The Trump administration has moved to classify more than 6,000 living immigrants as dead, canceling their Social Security numbers and effectively wiping out their ability to work or receive benefits in an effort to get them to leave the country, according to two people familiar with the situation.

The move will make it much harder for those affected to use banks or other basic services where Social Security numbers are required. It’s part of a broader effort by President Donald Trump to crack down on immigrants who were allowed to enter and remain temporarily in the United States under programs instituted by his predecessor, Joe Biden.

The Trump administration is moving the immigrants’ names and legally obtained Social Security numbers to a database that federal officials normally use to track the deceased, according to the two people familiar with the moves and their ramifications. They spoke on condition of anonymity Thursday night because the plans had not yet been publicly detailed.

The officials said stripping the immigrants of their Social Security numbers will cut them off from many financial services and encourage them to “self-deport” and abandon the U.S. for their birth countries.

It wasn’t immediately clear how the 6,000-plus immigrants were chosen. But the Trump White House has targeted people in the country temporarily under Biden-era programs, including more than 900,000 immigrants who entered the U.S. using that administration’s CBP One app.

On Monday, the Department of Homeland Security revoked the legal status of the immigrants who used that app. They had generally been allowed to remain in the U.S. for two years with work authorization under presidential parole authority during the Biden era, but are now expected to self-deport.

Meanwhile, a federal judge said Thursday that she was stopping the Trump administration from ordering hundreds of thousands of Cubans, Haitians, Nicaraguans and Venezuelans with temporary legal status to leave the country later this month.

A representative from the Social Security Administration did not respond to a request for comment on the news that living immigrants were being classified as dead. The agency maintains the most complete federal database of individuals who have died, and the file contains more than 142 million records, which go back to 1899.

The Privacy Act allows the Social Security Administration to disclose information to law enforcement in limited circumstances, which includes when a violent crime has been committed or other criminal activity.

DHS and the Treasury Deprartment signed a deal this week that would allow the IRS to share immigrants’ tax data with Immigration and Customs Enforcement for the purpose of identifying and deporting people illegally in the U.S. The agreement will allow ICE to submit names and addresses of immigrants inside the U.S. illegally to the IRS for cross-verification against tax records.

The acting IRS commissioner, Melanie Krause, who had served in that capacity since February, stepped down over that deal.

In March, meanwhile, a federal judge temporarily blocked a team charged with cutting federal jobs and shrinking the government led by billionaire Elon Musk from Social Security systems that hold personal data on millions of Americans, calling their work there a “fishing expedition.”

Skye Perryman, president and CEO of Democracy Forward, an advocacy group that has challenged various Trump administration efforts in court, said her organization would likely sue over the Social Security numbers as well, once more details become available.

“This President continues to engage in lawless behavior, violating the law and abusing our systems of checks and balances,” Perryman said.