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Federal Agencies Track Immigrants at the Border Using Purchased Cell Phone Data

Reports Privacy

Earlier this month, The Wall Street Journal reported that the Department of Homeland Security (“DHS”) has been purchasing access to the location data of millions of cell phones in America since 2017. This information has been used detect and later arrest undocumented immigrants who may be entering the United States illegally. In one case, US Immigration and Customs Enforcement (“ICE”) used the data to uncover an underground tunnel from Mexico to a KFC in Arizona; the restaurant owner was eventually arrested, though without any mention of the location data in the police records. Although ICE initially used the location data in its investigation of human-trafficking and drug-smuggling operations, the data was later shared with the deportation branch of ICE.

The company selling location data to DHS is Venntel, a small company whose website says it “supports national interests through technological innovation.” The company itself purchases its location data from private marketing companies that typically sell to advertisers, and further shares several executives and patents with Gravy Analytics, a major presence in the mobile-advertising world. Geotargeted mobile marketing, on which $21.4 billion was spent in 2018, allows advertisers to use cell phone location data in order to deliver tailored ads to consumers. The data provided to DHS is de-linked from cell phone owners’ names, but can still be used to identify and track individuals.

In 2018, the Supreme Court recognized the power of cell phone location data through its holding in Carpenter v. United States, 138 S.Ct. 2206 (2018): the government must obtain a search warrant before acquiring seven or more days of cell-site location information in the course of a criminal investigation. In Carpenter, the police accessed Timothy Carpenter’s cell phone location data collected by cell towers in an attempt to connect him to several robberies. In its reasoning, the Court said that individuals had a reasonable expectation of privacy in the whole of their physical movements, and the Fourth Amendment protects the sensitive information revealed by detailed location data.

DHS argues Carpenter does not apply to its purchase of location data here: Carpenter’s holding was limited only to cell phone data collected directly from users’ phones, while in this case the government is a commercial purchaser from a private company. One DHS official compared the purchase of cell phone location data to “buying a widget,” placing the acquisition of data on firm legal ground, despite the fact that it is likely the largest trove of data deployed by US law enforcement. The agency also explicitly excludes cell tower data from the information it collects from Venntel. However, Tim Cushing of Techdirt suspects that the government’s data collection practices will eventually end up on “the wrong side of the Constitution,” and further argues that citizens voluntarily sharing information with a company would not necessarily want to share that data with the government. Such detailed location data could be used to discriminate, according to Dragana Kaurin, research fellow at the Berkman Klein Center for Internet and Society. ACLU staff Attorney Nathan Freed Wessler argues that accessing location information without a warrant, whether the government pays for it or not, “undermines Supreme Court precedent.” The ACLU plans to fight DHS’s purchase of cell phone location data.