WATCH: Tucker Carlson reveals how much spying the NSA does on American citizens

"A couple of days ago, we told you that the national security agency had read our emails and was effectively threatening us with them. Leaking them it's not a statement you would make lightly. No one wants to go on TV and say, the government is spying on American citizens."

Carlson played a 2006 interview of then Senator Joe Biden in which he spoke about the dangers of US intelligence agencies surveilling Americans. Biden said, "The real question here is what do they do with this information that they collect that does not have anything to do with Al-Qaeda. And we're going to trust the President and the Vice President of the United States that they're doing the right thing. Don't count me in on that."

Carlson continued, "So now Joe Biden is in charge of the national security apparatus and his administration has turned it on Americans, who he has redefined as combatants, domestic terrorists, white supremacists. Where does this go from here? We think we know, and we're deeply concerned about it. We know the NSA is collecting data from American citizens, spying on them. They have a heart attack if you call it spying, that's exactly what it is. Let's stop using BS language. It's spying."

The Fox News host showed a senior Microsoft executive in the house judiciary committee meeting Wednesday stating that most Americans would be stunned if they knew how often the federal government used secret orders to collect information on them, not just from Microsoft, but also from Facebook, Apple, Google, Twitter, and others.

Carlson then called for an investigation into what exactly is going on and cited Florida Republican Congressman Matt Gaetz who called for that Wednesday in the house, specifically because of Carlson’s allegations.

Carlson continued, "They gather the information and they threaten you with it. Information is power. The more they have, the more power they have over you. And if they don't like your politics, it's a problem.” He also noted that the House minority leader, Kevin McCarthy, Republican of California has called for that investigation by the House Intelligence Committee."

The Fox News host then interviewed Glenn Greenwald who broke the original story of the NSA's mass surveillance program under the Obama administration. Carlson stated, "So, your position on this has remained consistent for more than a decade American citizens, unless they pose some obvious national security threat, imminent national screen threats, shouldn't be targeted by their own government." He then asked Greenwald, "Why is that not the position of everyone in general?"

Greenwald answered, "When I did the reporting with Edward Snowden in 2013 and 2014, liberals loved that reporting so much that they gave us every award that they had to offer…my work with Edward Snowden was given an Oscar… They couldn't lavish enough prizes and praise on us. And now here we are after the Trump years. And we know that the Democratic party and journalism in general has aligned. The CIA, the NSA and the FBI has aligned and merged with the security state. And so, in response to the report that you did, you would think other journalists just out of self-interest, even if they dislike your ideology and you would say, we want to know whether the NSA is abusing their powers in order to spy on you… and instead they mocked it. They said that, 'oh, he has to be paranoid in order to think this.'"

Greenwald then addressed the NSA’s statement to Carlson about the alleged spying. "They took the NSA statement that I have seen over and over Tucker, over the last eight years, that is designed to mislead the public. They use their carefully constructed words to say, Tucker Carlson is not an intelligence target of the NSA, which may be true. But what that leaves out is that there are so many other ways that they have to spy on the communications of American citizens without making you a target, without getting a warrant. They have huge authorities that really haven't been reigned in since 2013 and 2014."

Greenwald added, "I'm glad to hear Kevin McCarthy, other GOP leaders calling for an investigation, but the reality is that in bipartisan Washington, Nancy Pelosi and Chuck Schumer have been joining with the likes of Kevin McCarthy and Mitch McConnell to expand the NSA, to kill any attempts to reform it. So, these are kind of empty words."

Carlson agreed with the journalist that Mitch McConnell is a hundred percent on board with what they do. And then said, "I got a number of calls and texts today, one from Politico, asking me, well, who are you emailing? You would never claim your emails are being read by the government unless you could prove it again. You just sound like a crazy person. We can prove it. It happened, but now the line is, well, you must've been emailing the wrong people. I was under the impression as a journalist and an American citizen."

The Fox News host then asked Greenwald, "I have the right to email anybody I want. Is that not the standard any longer?"

Greenwald answered, "Tucker, ponder the authoritarianism needed for them to say that. Think about the premise there. They're saying that if you talk to somebody that the NSA has decided should be spied upon, it means that that person, even though they've been charged with no crime and convicted. Thing is up to no good. They're like a terrorist or a threat and you yourself are also.

"The whole point of the reporting that we did is that the NSA spies on millions and millions of people, indiscriminately, if you're a journalist, it's almost impossible not to talk to a targeted the NSA. They target everybody constantly all the time. That's why they're this huge sprawling agency. But the authoritarianism that is pervading journalism says if you're talking to somebody, the NSA, doesn't like, you're a bad person."