"Surveillance"

Surveillance is the systematic observation and monitoring of a person, population, or location, with the purpose of information-gathering, influencing, managing, or directing.

It is widely used by governments for a variety of reasons, such as law enforcement, national security, and information awareness. It can also be used as a tactic by persons who are not working on behalf of a government, by criminal organizations to plan and commit crimes, and by businesses to gather intelligence on criminals, their competitors, suppliers or customers. Religious organizations charged with detecting heresy and heterodoxy may also carry out surveillance. Various kinds of auditors carry out a form of surveillance.

Surveillance is done in a variety of methods, such as human interaction and postal interception, and more recently closed-circuit television (CCTV) cameras.

Surveillance can unjustifiably violate people's privacy and is often criticized by civil liberties activists. Democracies may have laws that seek to restrict governmental and private use of surveillance, whereas authoritarian governments seldom have any domestic restrictions. Increasingly, government and intelligence agencies have conducted surveillance by obtaining consumer data through the purchase of online information. Improvements in the technology available to states has led to surveillance on a mass and global scale.

Espionage is by definition covert and typically illegal according to the rules of the observed party, whereas most types of surveillance are overt and are considered legal or legitimate by state authorities. International espionage seems to be common among all types of countries.