Screenshot by CNET/"Last Week Tonight with John Oliver"

Edward Snowden and an unlikely interviewer have squared-off on HBO over the leaks that exposed the National Security Agency's extensive surveillance programs.

Sunday's installment of "Last Week Tonight with John Oliver" included Oliver's trip to Russia to interview Snowden, the former NSA contractor who has released thousands of classified documents since 2013. Snowden, who has been charged with espionage by the US government, has lived in Russia for the past one and a half years to avoid prosecution.

Oliver, like his former boss Jon Stewart, has a knack for using comedy to transform complicated issues, such as Net neturality and now the NSA's spying, into easier-to-grasp subjects. While much of Snowden interview focused on Oliver's typical comical take on politics, things did turn contentious at one point when the HBO host challenged Snowden on whether he read all of the documents he handed over to journalists.

"I have evaluated all of the documents that are in the archive," Snowden said in response to Oliver asking him how many of the thousands of NSA documents he had read. After Oliver pushed him on whether he actually read each document, Snowden provided a non-answer, saying that he does "understand" what he handed over.

Oliver pounced, saying there's a "difference between understanding what's in the documents and reading what's in the documents." He went on to argue that actually reading the documents is important, given the significance of the material that Snowden leaked.

"Well, in my defense, I'm not handling anything anymore," Snowden argued. Oliver pressed on, saying that Snowden should take responsibility for handing over any documents "that could be harmful."

Snowden did acknowledge that the release of information can be harmful "if people act in bad faith" or if the information is handled -- as Oliver described it -- with "incompetence." Oliver specifically pointed to an improperly redacted document published by The New York Times that allowed anyone to see how the US government was combating al-Qaeda operatives in Mosul, Iraq. Snowden acknowledged that the redaction issue was a "problem."

The interview has taken some by surprise, considering Oliver, a former writer and guest host for the comedy news series "The Daily Show," has used his HBO show to take a comical stance on real-world politics. However, he often includes commentaries that, while still comedic, take a strong stance on topics.

After making Snowden squirm for five minutes or so, Oliver retreated back to his comedic side. He showed Snowden videos of people on the streets who were asked if they knew who Edward Snowden was. Nearly all of them guessed incorrectly, with some identifying him as the man behind Julian Assange's WikiLeaks.

In typical fashion, Oliver was able to illustrate a point through his comedy. He argued that Americans generally don't care as much about NSA surveillance -- especially foreign spying -- as Snowden would like.

Oliver turned his attention to the difference in interest between the Snowden leaks and last year's leak of nude celebrity pictures caused by an apparent hack of Apple iCloud accounts. Nude images of celebrities hit the Web, causing a frenzy. Oliver brought the issue full circle to Snowden, arguing that what Americans care most about -- indeed, more than how the NSA operates -- are "dick pics."

Oliver again showed Snowden a video featuring people on the streets who were interviewed on whether they would take issue with the NSA gaining access to private photos. Nearly all of them said they would have a problem with it.

With Snowden's help, Oliver went through the various NSA programs that have been leaked through his data dump, including Prism and Upstream, to see whether such pictures could be obtained and viewed by the NSA. In each case, Snowden explained how the programs could allow for such private pictures to be collected and viewed by NSA officials.

"Yeah, this is something where it's not actually seen as a big deal in the culture of NSA," Snowden said in response to a question on the collection and viewing of naked pictures of people within the government agency. "Because you see naked pictures all the time."

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Oliver's intention was clear: to make the impact of Snowden's leaks easier for the average person to understand. Snowden agreed it takes real technical know-how to appreciate how the NSA collects information. Conveying that in short sound bites is nearly impossible, he said.

"When you send your junk through Gmail, that's stored on Google's servers," Snowden said, explaining one way in which a "pic" could find its way to the NSA through the government's Prism program. "Google moves data from data center to data center -- invisibly to you without your knowledge -- your data could be moved outside the borders of the United States, temporarily. When your junk was passed by Gmail, the NSA caught a copy of that."

The NSA did not immediately respond to a request for comment.