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 organizations, such as organizations like the NSA, 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. At the same time, 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, analyzed by artificial intelligence systems, and then redistributed and made available to the general public globally in realtime. By country Privacy International's 2007 survey, covering 47 countries, indicated that there had been an increase in surveillance and a decline in the performance of privacy safeguards, compared to the previous year. Balancing these factors, eight countries were rated as being 'endemic surveillance societies'. Of these eight, China, Malaysia and Russia scored lowest, followed jointly by Singapore and the United Kingdom, then jointly by Taiwan, Thailand and the United States. The best ranking was given to Greece, which was judged to have 'adequate