Mass surveillance is the intricate surveillance of an entire or a substantial fraction of a population in order to monitor that group of citizens. The surveillance is often carried out by local and federal governments or governmental organisations, such as organizations like the NSA and the FBI, but it may also be carried out by corporations (either on behalf of governments or at their own initiative). Depending on each nation's laws and judicial systems, the legality of and the permission required to engage in mass surveillance varies. It is the single most indicative distinguishing trait of totalitarian regimes. It is also often distinguished from targeted surveillance.
Mass surveillance has often been cited as necessary to fight terrorism, prevent crime and social unrest, protect national security, and control the population. Conversely, mass surveillance has equally often been criticized for violating privacy rights, limiting civil and political rights and freedoms, and being illegal under some legal or constitutional systems. Another criticism is that increasing mass surveillance could lead to the development of a surveillance state or an electronic police state where civil liberties are infringed or political dissent is undermined by COINTELPRO-like programs. Such a state could be referred to as a totalitarian state.In 2013, the practice of mass surveillance by world governments was called into question after Edward Snowden's 2013 global surveillance disclosure on the practices by the National Security Agency (NSA) of the United States. Reporting based on documents Snowden leaked to various media outlets triggered a debate about civil liberties and the right to privacy in the Digital Age. Mass surveillance is considered a global issue. The Aerospace Corporation of the United States describes a near-future event they call the "GEOINT Singularity" in which everything on the surface of the earth will be monitored at all times and analyzed by artificial intelligence systems.