counterintelligence

/ˌˈkaʊntərɪnˌtɛlədʒəns/

Information and activity that helps to expose or eliminate spying or terrorist threats is counterintelligence. One of the things the CIA is responsible for is counterintelligence.

Governments spy on each other, and the action of spying is called intelligence or espionage. When a country works to oppose or uncover spying, it's counterintelligence, or counterespionage. In the United States, both the CIA and the FBI have counterintelligence units. The word has been used since 1940, from counter, "against," and intelligence, from the Latin intelligentia, "power of discerning." The sense of intelligence as "secret information from spies" dates from the 16th century.

Definitions of counterintelligence

1. noun

   intelligence activities concerned with identifying and counteracting the threat to security posed by hostile intelligence organizations or by individuals engaged in espionage or sabotage or subversion or terrorism
   types:

   counterespionage

   spying on the spies

   security intelligence

   intelligence on the identity and capability and intentions of hostile individuals or organizations that may be engaged in espionage or sabotage or subversion or terrorism

   censoring, censorship, security review

   counterintelligence achieved by banning or deleting any information of value to the enemy

   countersubversion

   the aspect of counterintelligence designed to detect and prevent subversive activities

   counter-sabotage

   counterintelligence designed to detect and counteract sabotage

   military censorship

   all types of censorship conducted by personnel of the armed forces

   national censorship

   censorship under civil authority of communications entering or leaving of crossing the borders of the United States or its territories or possessions

   type of:

   intelligence, intelligence activity, intelligence operation

   the operation of gathering information about an enemy