Surveillance ( or ) is the monitoring of the
behavior, activities, or other changing information, usually of people for the purpose of influencing, managing, directing, or protecting them. This can include observation from a distance by means of electronic equipment (such as
CCTV cameras), or interception of electronically transmitted information (such as
Internet traffic or phone calls); and it can include simple, relatively no- or low-technology methods such as human intelligence agents and
postal interception. The word comes from a
French phrase for "watching over" ("sur" means "from above" and "veiller" means "to watch"), and is in contrast to more recent developments such as
sousveillance.