Counterintelligence: Federal Bureau of Investigation

The Federal Bureau Of Investigation is the lead agency for exposing, preventing, and investigating intelligence activities on U.S. soil.  The Federal Bureau Of Investigation Counterintelligence Division uses its full suite of investigative and intelligence capabilities to combat counterintelligence threats, with its goals including: protecting the secrets of the U.S. Intelligence Community, using intelligence to focus investigative efforts, and collaborating with our government partners to reduce the risk of espionage and insider threats; protecting the nation’s critical assets, like our advanced technologies and sensitive information in the defense, intelligence, economic, financial, public health, and science and technology sectors; countering the activities of foreign spies-- through proactive investigations, the Bureau identifies who they are and stops what they’re doing; and keeping weapons of mass destruction from falling into the wrong hands, and using intelligence to drive the FBI’s investigative efforts to keep threats from becoming reality.

(From: https://www.fbi.gov/investigate/counterintelligence)