PHILADELPHIA (CBS)– A special guest visited the Parkway Central Library in Philadelphia Monday night via closed-circuit television.

Edward Snowden spoke to audience members from Russia about the current status of what he calls “The Surveillance State”.

Snowden is the former NSA contractor who revealed classified surveillance information about the United States in 2013.

Snowden joined the “Philadelphia author event” with author and investigative journalist Jeremy Scahill, who signed books at the event.