Surveillance is used by governments for intelligence gathering, prevention of crime, the protection of a process, person, group or object, or the investigation of crime. It is also used by criminal organizations to plan and commit crimes, and by businesses to gather intelligence on their competitors, suppliers or customers.
Surveillance can be viewed as a violation of privacy, and as such is often opposed by civil liberties activists. A liberal democracy may have laws which restrict domestic government and private use of surveillance. Authoritarian governments seldom have any domestic restrictions, and international espionage is common among all types of countries.
Concerns have been raised about surveillance with regards to the Internet of things. Where surveillance technology is used for identification, monitoring, location tracking or to gain access to buildings and networks.