The NSA spent billions of dollars building Xkeyscore to operate at a scale no civilian machine could match. Don’t waste your time searching for a mythical download. Instead, invest that energy in understanding how mass surveillance really works—and how to protect yourself from it.

Attackers capitalize on the curiosity surrounding surveillance tools to trick users into downloading trojans.

Xkeyscore is a top-secret computer system used by the United States National Security Agency (NSA). It was designed to collect and analyze internet data on a massive, global scale. The system first came to public light in 2013, thanks to the explosive disclosures made by former NSA contractor Edward Snowden.