The journalist who took part in breaking two attention-grabbing stories on government surveillance charged that the United States is interested in destroying privacy all over the world.
"There is a massive apparatus within the United States government that with complete secrecy has been building this enormous structure that has only one goal," Greenwald said on CNN's "Piers Morgan Live" on Thursday.
"And that is to destroy privacy and anonymity not just in the United States but around the world."
Greenwald's subsequent comments came just hours after The Guardian and The Washington Post both broke another bombshell report detailing a program dubbed as "PRISM." According to the reports, the program involves the National Security Agency and FBI tapping into the servers of nine leading Internet companies to extract information.
Greenwald jump-started Thursday's discussion over civil liberties and government surveillance with a report late Wednesday night that detailed the NSA's collection of data from millions of Americans' phone records.
"It's well past time that we have a debate about whether that's the kind of country and world in which we want to live," Greenwald said on CNN. "We haven't had that debate because it's all done in secrecy and the Obama administration has been very aggressive about bullying and threatening anybody who thinks about exposing it or writing about it or even doing journalism about it. It's well past time that that come to an end."
The Obama administration and some members of Congress have defended the use of the programs. Sens. Dianne Feinstein (D-Calif.) and Saxby Chambliss (R-Ga.) said the NSA's collection of phone data has been going on for seven years. Feinstein said it's about "protecting America."
"People like Dianne Feinstein and Saxby Chambliss can have press conferences threatening people for bringing light to what it is they're doing, but the only people who are going to be investigated are them," Greenwald said in response.
"It's well past time that these threats start to be treated with the contempt that they deserve."
Watch the clip below, via CNN: