Palantir, the data-mining firm co-founded by tech billionaire and Trump transition adviser Peter Thiel, has provided largely secret assistance to the US Customs and Border Protection agency (CBP) in operating a system that tracks and assesses immigrants and other travelers, according to public records. Known as the Analytical Framework for Intelligence, the system draws from a variety of federal, state, and local law enforcement databases that gather and analyze often-sensitive details about people, including biographical information, personal associations, travel itineraries, immigration records, and home and work addresses, as well as fingerprints, scars, tattoos, and other physical traits.

Records show that Palantir has played an apparently important, although largely undisclosed, role in US Customs and Border Protection intelligence

Training documents suggest Palantir has helped power a government program called the Analytical Framework for Intelligence, which privacy experts say could underlie Trump’s proposed “extreme vetting” of immigrants

In a two-and-a-half-day AFI training session, classes simply labeled “Palantir” occupy far more time than any other single subject

Among the information accessible within the AFI system is data collected by NSEERS, a Bush-era program that required foreign nationals from selected countries — all predominantly Muslim ones with the exception of North Korea — to register

CBP lends out access credentials for the Analytical Framework for Intelligence (AFI) to other law enforcement agencies, including the Immigration and Customs Enforcement’s office of Enforcement and Removal Operations, the country’s primary deportation force. Though little is understood by the public, the Palantir-linked system could represent a powerful and far-reaching tool in Trump’s quest to limit migration into the country.

“When Trump uses the term ‘extreme vetting’, AFI is the black-box system of profiling algorithms that he’s talking about,” says Edward Hasbrouck of the Identity Project, a civil liberties initiative that focuses on the rights of travelers. “This is what extreme vetting means.”

Dozens of heavily redacted references to Palantir appear in AFI documents that the Electronic Privacy Information Center obtained through a lawsuit.

AFI was implemented in August 2012 as an analytical superstructure and search engine to overlay some of the government’s largest databases of personal and travel information. According to a recent Department of Homeland Security (DHS) oversight report, federal agents can use AFI for a broad range of purposes, such as enforcing immigration laws and assisting field agents “in preventing the illegal entry of people and goods” into the country.

In a 2012 report, DHS highlights AFI’s ability allow agents to search information across varied databases, but Hasbrouck emphasizes that AFI’s most notable function might lay in what he says are top-secret algorithms that process personal data to assess travelers and would-be immigrants. This helps federal authorities determine a person’s eligibility to travel into — or even within — the United States, Hasbrouck says.

“When Trump uses the term ‘extreme vetting’, AFI is the black-box system of profiling algorithms that he’s talking about.”

In its 2012 oversight report DHS touts AFI’s various abilities to process data, which include “geospatial analysis” to help agents learn “about the location or type of location that is favorable for a particular activity,” link analysis to “produce a social network representation of the data,” and temporal analysis “that can be used to predict future activities.”

Since AFI’s inception in 2012, the system appears to have expanded significantly. This past September, DHS issued a notice stating that AFI was no longer merely a scaffold allowing agents to search and analyze various separate databases. In order to increase its efficiency, AFI has become its very own database: the system has begun copying the volumes of information it accesses into its own servers, a development that DHS acknowledged “presents privacy challenges as its functionality relies on continuous replication of data.”

Hasbrouck isn’t alone in his quest to learn more about AFI’s risk calculations, which he says can come into play, for example, anytime a traveler seeks to board a commercial airliner in the United States. The alleged existence of these algorithms were of primary interest to attorneys for the Electronic Privacy Information Center (EPIC), a different privacy group, in filing a lawsuit last year against CBP for records detailing AFI. As a result of the still-ongoing suit, the border control agency has released several hundred pages of material on the system, but the records are so heavily redacted they provide little insight.

AFI has become its very own database

John Tran, an attorney with EPIC, says that one of the most troubling aspects of AFI — and a motivation for his lawsuit — is how little the public knows about the program. “AFI generates risk assessments for travellers,” Tran said. “But we don’t know how the scores are being generated and what the factors are. What if there’s an error? Users should have an opportunity to correct the error, users should have an opportunity to understand what goes into generating the score.”

Yet the heavily blotted documents Tran obtained contain at least one notable feature: they make dozens of references to Palantir.

The records show that Palantir has played an apparently important, although largely undisclosed, role in CBP’s operation of AFI. It is evident from the redactions that the government has deemed most of Palantir’s AFI-related functions too secret to reveal publicly. Even so, the records do provide some insight into the scope, if not the details, of Palantir’s involvement with the intelligence system.

“I don’t think there’s any way to read it other than that Palantir is certainly involved with AFI,” said Tran. The documents, Tran said, suggest that Palantir has played an “active role in management and upkeep of the system.”

Classes labeled “Palantir” occupy far more time than any other single subject

One slide shows that, in a two-and-a-half-day AFI training session, classes simply labeled “Palantir” occupy far more time than any other single subject — spanning an entire day of the otherwise fragmented course. Another slide is fully blacked out under the title that reads “AFI: Palantir Quick Reference Card.” In a federal filing, attorneys for CBP said that disclosure of information regarding this Palantir function would endanger the program’s security and disrupt law enforcement investigations. “Palantir Quick Reference Card provides an overview of key elements, techniques which can be used by law enforcement officers and related keyboard shortcuts designed to assist in navigation of the Palantir application within AFI,” the filing reads. “Disclosure of this information could enable unauthorized users to gain access to the system and alter, add, or delete information altogether, thus destroying the integrity of the system.”

Records accessible via the federal government’s online contract database show that Palantir licenses were provided through the third-party firms Govplace, Akira Technologies, and All Points Logistics to CBP in three separate agreements between 2010 and 2013 that come out to nearly $1.5 million. Though the CBP contracts EPIC obtained do not contain visible references to Palantir, they do show agreements with Akira and All Points, among other firms, in which descriptions of the services provided are heavily redacted.

Throughout the documents, Palantir is often described as being a separate entity from AFI but also an important component of its operation. “The CBP AFI and Palantir data are accessible to AFI users,” reads one otherwise largely redacted passage. “AFI and Palantir are authorized to store/process sensitive but unclassified data and information.”

After it was reported last month that Peter Thiel, Palantir’s co-founder, had joined Donald Trump’s transition team, some observers expressed concern over potential conflicts of interest. Thiel’s company has contracts with the Department of Justice, the Defense Department, and the Central Intelligence Agency, among other agencies. Fears over Thiel’s potentially overlapping interests were heightened when, in response to media queries, Thiel declined to confirm that he had signed the Trump transition team’s standard agreement requiring its members to step away from areas of the transition from which they could personally benefit.

AFI is not the only link Thiel has to agencies that enforce immigration laws dear to Trump. Palantir also has a $34,650,000 contract with ICE to build and maintain an intelligence system called FALCON, which, like AFI, stores and analyzes information it receives from databases kept by various government agencies. FALCON is used by agents within ICE’s Office of Homeland Security Investigations (HSI), an office that focuses mostly on serious cross-border criminal activity. The office has conducted some of the agency’s most controversial immigration raids. In September, in Buffalo, New York, HSI agents raided several Mexican restaurants, resulting in the arrest of not only managers but also undocumented workers, some of whom were charged with criminal counts of “illegal re-entry,” causing an outcry from immigrant advocates.

Like the FALCON system, AFI can be applied to diverse areas of law enforcement, and it’s unclear what exact restrictions exist on the tool’s applications. CPB permits the tool to be used by a range of other enforcement agencies, including the US Coast Guard; US Citizenship and Immigration Services (USCIS), which operates Obama’s now-endangered Deferred Action for Childhood Arrivals program; and Immigration and Customs Enforcement (ICE). According to DHS, access to AFI has been given to ICE’s main deportation force, the Enforcement and Removal Operations, for the purpose of administering “immigration laws and other laws enforced by ICE.”

NSEERS data is accessible within the Palantir-linked AFI system

The 2012 report on AFI lists a number of mechanisms in place that seek to ensure that sensitive personal data is secure within the system and protected from abuse. These include auditing functions that record the search history of its users, authentication of user permissions, and internal controls to ensure that AFI access is only granted on a need-to-know basis. (The training documents EPIC obtained ask instructors to remind their students to refrain from using AFI to search for information about their neighbors, famous people, or themselves.)

CBP was unable to respond to an emailed list of questions and Palantir did not respond to a request for comment.

The 2016 report on AFI mentions one particularly controversial data source. Among the troves of information accessible within the Palantir-linked AFI system is a database containing information gleaned from the Bush-era program called National Security Entry-Exit Registration System, or NSEERS, which required foreign nationals from selected countries — all predominantly Muslim ones with the exception of North Korea — to register with the federal government. In recent weeks, the post-9/11 registration system, which critics called a de facto Muslim registry and which Obama suspended in 2011, has been back in headlines as the Trump transition team is reportedly considering plans to either reinstate the program or build something similar.

Regardless of Trump’s plans for NSEERS, federal agents are still apparently able to draw upon data collected years ago by the now-defunct program.

“They phased out the program, but that doesn’t mean they’re purging the data,” said Hasbrouck. “And that’s part of the problem: This stuff lives on forever.”

Through a lawsuit, the Electronic Privacy Information Center (EPIC) obtained heavily redacted documents related to training agents on how to use Analytical Framework for Intelligence.