An NSA document from 2008, titled “Exploiting Terrorist Use of Games & Virtual Environments,” was published Monday by The Guardian in partnership with The New York Times and ProPublica.
In the report, the agency warned of the risk of leaving games communities under-monitored and described them as a "target-rich communications network" where intelligence targets could “hide in plain sight.”
The document showed that the US and UK spy agencies were collecting large amounts of data in the Xbox Live console network, which has more than 48 million players.
Real-life agents have been deployed into the World of Warcraft multiplayer online role-playing game and the virtual world of Second Life, in which people interact with each other through avatars.
The NSA and GCHQ also tried to recruit potential informants among the gamers, the report said.