Surveillance is the monitoring of behavior, many activities, or information for the purpose of information gathering, influencing, managing, or directing. This can include observation from a distance by means of electronic equipment, such as closed-circuit television (CCTV), or interception of electronically transmitted information like Internet traffic. Increasingly, governments may also obtain consumer data through the purchase of online information, effectively expanding surveillance capabilities through commercially available digital records. It can also include simple technical methods, such as human intelligence gathering and postal interception.
Surveillance is used by citizens, for instance for protecting their neighborhoods. It is widely used by governments for intelli
gence gathering, including espionage, 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 criminals, their competitors, suppliers or customers. Religious organizations charged with detecting heresy and heterodoxy may also carry out surveillance.Auditors carry out a form of surveillance.
Surveillance cameras, or security cameras, are video cameras used for the purpose of observing an area. They are often connected to a recording device or IP network, and may be watched by a security guard or law enforcement officer. Cameras and recording equipment used to be relatively expensive and required human personnel to monitor camera footage, but analysis of footage has been made easier by automated software that organizes digital video footage into a searchable database, and by video analysis software (such as VIRAT and HumanID). The amount of footage is also drastically reduced by motion sensors which record only when motion is detected. With cheaper production techniques, surveillance cameras are simple and inexpensive enough to be used in home security systems, and for everyday surveillance. Video cameras are one of the most common methods of surveillance.
As of 2016, there are about 350 million surveillance cameras worldwide. About 65% of these cameras are installed in Asia. The growth of CCTV has been slowing in recent years.In 2018, China was reported to have a huge surveillance network of over 170 million CCTV cameras with 400 million new cameras expected to be installed in the next three years, many of which use facial recognition technology.