Former NSA whistle-blower Edward Snowden revealed the massive US global surveillance program.
PRISM is the code name of a high-level clandestine surveillance program of the US National Security Agency.
Under the highly classified program, the US National Security Agency and the Federal Bureau of Investigation have been tapping directly into the central servers of nine U.S. internet companies, extracting audio, video, photographs, e-mails, documents and connection logs that enable analysts to track a person's movements and contacts over time.
The NSA has conducted more than 61,000 hacking operations across the globe.