Tear gas rises during a standoff with U.S. Immigration and Customs Enforcement (ICE) and federal officers in the Little Village neighborhood of Chicago, Illinois, U.S., October 4, 2025. REUTERS/Jim Vondruska
US Immigration and Customs Enforcement paid $825,000 this year for surveillance tech that can spy on nearby mobile phones. TechCrunch identified the contract, which "provides Cell Site Simulator (CSS) Vehicles to support the Homeland Security Technical Operations program," in public records. This isn't the first time ICE has used cell-site simulators, but the agency has recently drawn outcry for actions such as unlawfully detaining US citizens and using violence against journalists and protestors as it carries out the immigration enforcement ordered by President Donald Trump.
TechOps Specialty Vehicles supplied the vehicles equipped with cell-site simulators, also known as IMSI-catchers, in this contract with ICE. IMSI stands for "International Mobile Subscriber Identity," and is a unique identifier for every user on a cellular network. Cell-site simulators act as fake cellular towers that can eavesdrop on any mobile phone in the nearby area when a user connects to the actual cellular towers of their service provider.
There are active and passive versions of IMSI catchers. The passive ones are less intrusive, but the active IMSI catchers can intercept all data transferred from mobile phones as well as tracking the phones' location. The TechCrunch report didn't uncover which version is being used by ICE. This surveillance tech can also interfere with a targeted phone's ability to contact emergency services via 911, posing a safety risk. It is also controversial since it doesn't involve obtaining a warrant and can expose innocent bystanders' information to the government.