ICE Homeland Security Investigations executed a nationwide operation targeting illegal SIM box operations run by transnational criminal organizations between June 22 and July 10. The mission, dubbed Operation Signal Break, dismantled critical command-and-control infrastructure used to perpetrate large-scale telecommunications fraud across the United States, according to a July 24 announcement.
Led by the Department of Homeland Security Cyber Crimes Center with assistance from HSI Los Angeles, Operation Signal Break mobilized specialized “SIM Box Surge Teams” consisting of special agents, criminal analysts, and computer forensics analysts to high-risk areas in California, Florida, Texas, Massachusetts, New York, and New Jersey. More than 11 HSI field offices participated in the coordinated effort.
Since 2024, HSI has executed over 116 federal criminal search warrants related to illegal SIM box operations. Authorities have seized more than 500,000 SIM cards, over 1,900 SIM boxes, and more than $700,000 in illicit proceeds. These investigations have resulted in one criminal arrest and eleven administrative arrests as well as the disruption of sixty-eight SIM farms across fifteen states used for fraudulent texts and calls. Officials said actions were often coordinated across regions to prevent organizations from reconfiguring their infrastructure.
“I commend our special agents for their outstanding dedication and teamwork in dismantling illicit telecommunications infrastructure. Their relentless pursuit of justice and commitment to protecting the integrity of our communications networks have made our communities safer and sends a clear message to those seeking to exploit our systems to defraud Americans,” said HSI acting Executive Associate Director John Condon. “This success is a testament to the skill and determination of our HSI team.”
SIM farms are collections of devices—known as SIM boxes—that house hundreds or thousands of cellphone SIM cards. These devices enable criminals to route massive volumes of calls and text messages over the internet while disguising origins for activities such as scam calls or phishing texts. These operations cost Americans an estimated $15 million each year, according to the Federal Trade Commission.
HSI Los Angeles will analyze seized data with partners including the Counter Threat Finance Unit and Cross Border Financial Crimes Center in order to identify victims, quantify losses, and trace proceeds linked with Chinese transnational criminal organizations. This analysis is expected to support further indictments as well as asset seizures targeting both domestic and overseas infrastructure.