Law enforcement is now buying cellphone location data from marketers

An ICE agent arrests a man in Los Angeles. | John Moore/Getty Images

This is no longer a matter of creepy ads following you around the internet.

Companies that sell your cellphone location data to marketers are also selling that information to Immigration and Customs Enforcement (ICE), the government body known for detaining children in cages. According to a new report by the Wall Street Journal, ICE and its affiliated organizations at the Department of Homeland Security (DHS) have been using location information for “millions” of cell phones bought from marketers to track down and arrest undocumented immigrants at the US-Mexico border.

The effort seems to be massive and legal. And as WSJ points out, “The federal government’s use of such data for law enforcement purposes hasn’t previously been reported.”

Experts told the Journal that these are the “largest known troves of bulk data being deployed by law enforcement in the US.” Venntel, a company that licenses location data and is affiliated with the mobile ad company Gravy Analytics, has received $250,000 in contracts in the past few years from DHS, which operates ICE. Public records show that Venntel has also received a contract from the Drug Enforcement Agency (DEA).

Homeland Security officials wouldn’t tell WSJ exactly how it leverages location data. It’s possible that the agency can use the information to see where people are crossing the border — for instance, in locations outside of regulated entry ports — and plan detention efforts accordingly. Documents reviewed by the Journal “make oblique references to such data being used to track, among other things, tunnels along the border.” The use of data does not sound dissimilar to certain marketing strategies. Advertisers can use anonymized geolocation data from cellphones to target people when they visit, say, a McDonald’s location.

As Recode has previously reported, DHS has stated that its organizations acquire “commercially available location data” from “third-party data providers” to “detect the presence of individuals in areas between Ports of Entry where such a presence is indicative of potential illicit or illegal activity.”

A 2018 Supreme Court case determined that cellphone location data is protected and that law enforcement needs warrants to collect it. As the Journal reports, however:

The federal government has essentially found a workaround by purchasing location data used by marketing firms rather than going to court on a case-by-case basis. Because location data is available through numerous commercial ad exchanges, government lawyers have approved the programs and concluded that the Carpenter ruling doesn’t apply.

The data they’re using doesn’t include personally identifiable information like a user’s name, but rather an anonymized alphanumeric ID. Still, as a New York Times investigation into this type of data showed late last year, it’s pretty easy to figure out who someone is based solely on their location. If a person spends every night at a certain location and working hours on weekdays at another location, for example, it’s relatively straightforward to determine where that person lives and works. Using those two bits of information, only minor internet sleuthing is necessary to figure out who that person is, not to mention loads of other info about them.

And as we’ve said before, free software like the weather or gaming app on your phone is never free. It’s common for free software and services — anything from antivirus software to your weather or gaming app — to sell your personal information, including your location, to data brokers that can then sell it to other entities and even law enforcement. In other words, free software can come at a significant cost to your privacy. The terms of the exchange are embedded deep in the privacy policies we never read.

This is no longer a matter of creepy ads following you around the internet. It could be law enforcement, too.