The Oversight Project — part of the powerful right-wing think tank the Heritage Foundation — claimed this week that it used mobile ad data from cell phones to track the movements of Thomas Crooks in the year leading up to his attempted assassination of former President Donald Trump at a Pennsylvania rally earlier this month.

“We found the assassin’s connections through our in-depth analysis of mobile ad data to track movements of Crooks and his associates,” the Oversight Project wrote on social media on Monday, explaining that it had identified nine “devices that were located at Crook’s home and his work within the past year.”

The organization suggested that Crooks may have had some connection to the FBI before the shooting, writing: “Someone who regularly visited Crooks home and work also visited a building in Washington, DC located in Gallery Place. This is in the same vicinity of an @FBI office on June 26, 2023. Who’s device is this?”

The post was catnip for MAGA conspiracy theorists who believe the “deep state” — entrenched bureaucrats in federal agencies and law enforcement — has been trying to sabotage, arrest and now kill Trump.

But beyond the implied conspiracy, which experts told HuffPost has little substance, the Heritage Foundation’s use of mobile ad data signifies a new era of political organizations tracking the movements of American citizens.

That the Heritage Foundation ― which spearheaded Project 2025, the blueprint for an authoritarian second Trump administration, and whose CEO earlier this month warned of potential “bloodshed” with the “radical left” ― has this data raises particular privacy concerns.

The Heritage Foundation did not respond to an email in which HuffPost asked the organization how it acquired the mobile ad data used to purportedly track Crooks’ movements, as well as a request to review the data.

Mobile ad data, which is what the Oversight Project said it used, comes from apps that know a person’s location, such as weather and gaming apps. Those apps sell that data to advertising entities, some of which will then sell that data to third parties.

One of the most famous examples of mobile ad data being used for investigations involved a Catholic priest who was found to be using Grindr, the gay dating and hookup app.

“It’s not that Grindr was making location data available for sale,” said Byron Tau, a reporter at NOTUS and author of the book “Means of Control: How The Hidden Alliance of Tech and Government Is Creating A New American Surveillance State.”

“It’s that Grindr was serving ads on its app, and when you do that, you open your users up to having that data collected by these advertising entities that are sitting on the networks that serve the app.”

“It’s kind of a shadowy market,” he added. “These are companies that are not household names. They often are small data brokers or small companies, and some of them will sell you the raw data, some of them will sell you an analytical tool to look at it, but at the end of the day they have the movement records of hundreds of millions of devices, and it’s commercially available.”

Murat Kantarcioglu, a computer science professor at the University of Texas at Dallas who heads up the school’s Data Security and Privacy Lab, said the Oversight Project’s claims about its investigation into Crooks should be taken with a giant grain of salt.

The Oversight Project’s implication that someone associated with Crooks visited a part of D.C. “in the vicinity” of an FBI office doesn’t necessarily indicate the person was visiting the FBI office itself, Kantarcioglu noted. Downtown D.C. is a busy urban area, with a ton of restaurants and businesses, including an arena. Mobile ad data, he said, while accurate within a certain distance, can’t always pinpoint someone to a precise address.

Moreover, Kantarcioglu said, if the FBI was truly involved in some kind of grand conspiracy with Crooks ahead of the assassination attempt — visiting him at his home in Pennsylvania, for example — the data reviewed by the Oversight Project would prove the agents involved were incredibly sloppy. FBI agents would surely know enough to not let the apps on their phone track their movements, as such data could become widely available.

Tau said there are reasons to be wary of investigations that rely on mobile ad data.

“We’ve all had instances where our GPS on our phone thinks we’re somewhere on a different highway that we’re not on, and so there can be errors,” he said. “It could show you in your neighbor’s home, for example. But in general it’s accurate enough.”

“We’ve all had instances where our GPS on our phone thinks we’re somewhere on a different highway that we’re not on, and so there can be errors,” he said. “It could show you in your neighbor’s home, for example. But in general it’s accurate enough. The problem is there is a small incentive to commit fraud. So a lot of these data brokers, because the data is valuable, have to contend with apps who fake data. So it’s possible that the data is not real. It does happen.”

And accurate “enough” isn’t always enough to draw the kinds of conclusions conspiracists look for. The 2022 movie “2,000 Mules,” directed by far-right conspiracist Dinesh D’Souza, claimed that Democratic “mules” during the 2020 election were paid to illegally drop off ballots in ballot boxes across the country, swinging the election in favor of President Joe Biden. But an Associated Press analysis of the movie’s claims revealed that the filmmakers used an “improper analysis of cellphone location data, which is not precise enough to confirm that somebody deposited a ballot into a drop box.”

“It’s not really surprising to me that private organizations have discovered that they can use this kind of telemetry data or location data that’s available for sale to do their own investigations,” Tau said. “We’ve seen journalists use it. We’ve seen nonprofits use it. And it’s not really a surprise that partisan political groups are getting in on the game.”

Kantarcioglu noted that the Heritage Foundation has used mobile ad data for investigations before. In 2022, the Oversight Project released a report stating that it had tracked the locations of about 30,000 cell phones at migrant shelters and Customs and Border Protection facilities, in an effort to track where these migrants traveled in the U.S. after crossing the southern border.

Heritage stated in its report that the cell phone data was used to “test the anecdotal reporting that the movement of illegal aliens through the United States is being facilitated not just by the federal government under President Joe Biden and [DHS] Secretary Alejandro Mayorkas, but also by [non-governmental organizations].”

The organization was tracking migrants’ movements, in essence, to fearmonger about them. Heritage, and the wider MAGA movement in which it is firmly entrenched, have long sought to portray migrants as criminals, rapists and murderers.

That Heritage tracked migrants’ movements is concerning, considering what Heritage would like to do with them.

“We need to have the biggest mass deportation system ever in the history of America because it is unjust, illegal, and evil that more than 10 million illegal aliens have come to this country,” Heritage President Kevin Roberts said on MSNBC last month.

Roberts helped spearhead Project 2025, which calls for mass deportations and the suspension of due process for migrants. (Trump himself has called for the mass deportation of millions of immigrants, who he said are “poisoning the blood of our country,” rhetoric that bears an unnerving resemblance to that deployed by Nazi dictator Adolf Hitler.)

But migrants may not be the only group Roberts has his eye on. Last month on the far-right channel Real America’s Voice, Roberts suggested he was ready to take up arms in the fight against the “radical left.”

“We are in the process of the second American Revolution,” he said, “which will remain bloodless if the left allows it to be.”