WASHINGTON ― The Obama administration is dismantling an inactive national registry that was used to track foreign visitors from a designated list of countries, most of which have Muslim-majority populations. The move represents a last-minute effort by the outgoing president to delay his successor, Donald Trump, from reinstating what critics say would amount to a Muslim registry.

The registry, known as National Security Entry-Exit Registration (NSEERS), was created shortly after the Sept. 11 attacks. It required men 16 and older from certain countries to register in person with the Immigration and Naturalization Service and submit to questioning and fingerprinting when entering the U.S. By 2003, the list of designated countries had swelled from a handful to 25, with 24 of them majority-Arab or Muslim.

The Department of Homeland Security is removing the regulatory structure behind NSEERS, effective immediately, the agency said in a statement on Thursday.

The administration of President George W. Bush found the program to be ineffective and stopped using it after only a year and a half. With the program already obsolete by the time Obama entered office, his administration de-listed the countries designated under NSEERS, effectively suspending the program.

But the regulatory structure behind it remained in place, prompting fears that Trump, who spoke during the campaign about banning Muslims from entering the country, would use the framework to quickly reinstate it.

Last month, 200 human rights, civil liberties and interfaith groups urged the Obama administration to rescind the NSEERS regulatory framework before handing the presidency over to Trump. During the short period the registry was active, the groups wrote in a letter to Obama, it had a devastating effect on the people targeted.

“Families were torn apart, small businesses in immigrant neighborhoods closed their doors, and students discarded their educational aspirations,” the letter read.

The national registry, which didn’t lead to a single terrorism conviction, was also wildly ineffective, according to former government officials.

“The people who could be identified as terrorists weren’t going to show up,” former INS commissioner James W. Ziglar told The New York Times in 2004. “This project was a huge exercise and caused us to use resources in the field that could have been much better deployed.’”

An expansive, generalized search is an ineffective way to look for a small group of wrongdoers, former FBI agent Michael German told The Huffington Post last month.

“NSEERS looks at tremendous numbers of people who are not suspected of any wrongdoing,” German said. “The likelihood of that type of system somehow tripping upon somebody who is otherwise unknown is pretty small.”

In 2012, the DHS inspector general found that Customs and Border Patrol officers tasked with processing information from registrants saw NSEERS as an “inefficient use of resources.”

When the program was launched in 2002, there were more than 250,000 entry and exit registrations. CBP officers told the inspector general “there was little value in the interviews they conducted with NSEERS registrants” and that their time would be better spent doing more targeted investigations.

Reinstating a national registry that predominantly targets Muslims entering the U.S. appears to be a top priority for the incoming Trump administration. Weeks after winning the election, Trump met with Kansas Secretary of State Kris Kobach (R), who was the architect of NSEERS when he served in the Bush administration’s Justice Department. Kobach, at the time thought to be in the running for Homeland Security secretary, was photographed entering the meeting with Trump carrying notes that read:

Update and reintroduce the NSEERS screening and tracking system (National Security Entry-Exit Registration System) that was in place from 2002-2005. All aliens from high-risk areas are tracked.

Add extreme vetting questions for high-risk aliens: question them regarding support for Sharia law, jihad, equality of men and women, the United States Constitution.

Trump didn’t end up choosing Kobach to head DHS, but his recommendations are in line with what Trump has been pledging to do once he enters the White House.

The Obama administration’s move to rescind the regulatory framework does not preclude Trump from reinstating it, making the outgoing president’s action a largely symbolic effort to avoid complicity in actions taken by his successor.

Still, it would at least slow down the process of recreating the registry and could open up the process to more public scrutiny.

The next administration would likely have to “publish a rule, run a public notice and comment period, and then let a period run before the rule is effective,” said Shoba Sivaprasad Wadhia, director of the Center for Immigrants’ Rights Clinic at Penn State Law.

It’s also possible there will be “legal challenges to any version of a registry that violates U.S. law,” Wadhia said.