Immigration and Customs Enforcement agents have been using cell-site simulators to track phones without consistently following federal protocols, according to a Department of Homeland Security Inspector General report that has renewed constitutional privacy concerns.
How the Technology Works
Cell-site simulators function by mimicking legitimate cellphone towers, causing nearby mobile devices to automatically connect to their signals. The technology allows ICE agents to identify and track specific phones with precision. According to DHS policy guidelines, these devices can only collect signal strength data and general device direction. The simulators cannot access communication content such as emails, text messages, contact lists, or stored images, authorities maintain.
The American Civil Liberties Union disputes this limited scope, reporting that the simulators can reveal the identity of every phone within a specific coverage area. This means devices belonging to individuals not under investigation are also captured in the surveillance net, raising questions about the breadth of data collection during enforcement operations.
Compliance Failures Documented
The Inspector General’s internal review found that both the Secret Service and ICE’s Homeland Security Investigations office failed to follow federal statutes and internal policies during criminal investigations. While agencies obtained search warrants in reviewed cases, they did not always secure court orders required under the Pen Register Act. The review also found HSI violated the E-Government Act of 2002 by operating without an approved Privacy Impact Assessment until January 2022.
Resource limitations and personnel changes prevented the required privacy assessment, making it impossible to identify or mitigate risks to collected data before operations began. The compliance gaps occurred most frequently during situations authorities classified as urgent, though specific case details were not disclosed in the report.
Constitutional Questions
Chris Weiland, president of Restore the 4th Minnesota, stated that using this data without proper court orders may violate the Fourth Amendment’s protection against unreasonable searches and seizures. Cooper Quintin, senior technologist at the Electronic Frontier Foundation, expressed concern about agencies possessing advanced surveillance capabilities. Privacy advocates question how collected data is stored, who can access it, and whether information gathered on non-targets is properly deleted.
The technology review comes as the Trump administration pursues expanded deportation enforcement, placing additional scrutiny on tools used by immigration authorities. Questions about proper oversight and constitutional protections remain unresolved as ICE continues deploying cell-site simulators in field operations.
