Homeland Security Investigations (HSI) is a division of U.S. Immigration and Customs Enforcement (ICE) under the Department of Homeland Security (DHS). HSI is responsible for investigating a wide range of criminal activities that threaten national security, including cybercrime, human trafficking, financial crimes, immigration violations, and digital surveillance. HSI works with domestic and international partners to combat cyber threats, enforce laws related to digital security, and protect critical infrastructure. The agency uses advanced technology and intelligence-driven strategies to identify, disrupt, and dismantle cybercriminal organizations and other threats to the United States.