Espionage or spying is the act of obtaining secret or confidential information from non-disclosed sources or divulging of the same without the permission of the holder of the information. A person who commits espionage is called an espionage agent or spy. Any individual or spy ring (a cooperating group of spies), in the service of a government, company or independent operation, can commit espionage. The practice is clandestine, as it is by definition unwelcome. In some circumstances, it may be a legal tool of law enforcement and in others, it may be illegal and punishable by law.
The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject. (February 2019)
Espionage is often part of an institutional effort by a government or commercial concern. However, the term tends to be associated with state spying on potential or actual enemies for military purposes. Spying involving corporations is known as industrial espionage.
One of the most effective ways to gather data and information about a targeted organization is by infiltrating its ranks. This is the job of the spy (espionage agent). Spies can then return information such as the size and strength of enemy forces. They can also find dissidents within the organization and influence them to provide further information or to defect. In times of crisis, spies steal technology and sabotage the enemy in various ways. Counterintelligence is the practice of thwarting enemy espionage and intelligence-gathering. Almost all nations have strict laws concerning espionage and the penalty for being caught is often severe. However, the benefits gained through espionage are often so great that most governments and many large corporations make use of it.