Edward Snowden's release of secret NSA surveillance methods used against the America public makes him the most admirable and important whistleblower in national security history.

That's essence of comment by Pentagon Papers leaker Daniel Ellsberg, left, the nation's most-honored whistleblower.

“There’s no American official or former official that I admire more at this point,” Ellsberg said of Snowden to a reporter. “There’s never been a more important disclosure to the American people than the leak — and I include the Pentagon Papers in that.”

Ellsberg also said of Snowden, 29, shown at right in a Guardian photo, “He’s clearly ready to give his life or his freedom for the interests of his country.” Meanwhile, Senate Intelligence Committee Chair Dianne Feinstein, a California Democrat married to a major federal contractor, adjudged Snowden guilty of “treason” and said he should be punished in keeping with that determination.

This column provides other expert assessment on Snowden's actions, and addresses questions about the surveillance. It concludes with an appendix of other commentary. As the dust settled, the major mysteries remained, as indicated by: 5 Basic Things We Still Do Not Know about NSA Snooping.

The Guardian published a video of Snowden's eloquent description of his reasons for risking imprisonment. He said he wanted to alert the American public to the danger it faces from surveillance of potentially any electronic communications by phone and social media.

Snowden, the source behind the biggest intelligence leak in the NSA's history, explained to the Guardian team of Glenn Greenwald, Ewen MacAskill, and videographer Laura Poitras “his motives, his uncertain future and why he never intended on hiding in the shadows.”

Snowden said of his freedom and the rest of his future, “I'm willing to sacrifice all of that because I can't in good conscience allow the US government to destroy privacy, internet freedom and basic liberties for people around the world with this massive surveillance machine they're secretly building.”

Ellsberg's praise of Snowden was based partly on Snowden's rare choice to take responsibility for his actions before authorities outed him. Others prominent in national security whistleblowing and related civil rights advocacy also praised Snowden, a onetime Army recruit injured in training for Iraq service.

“He’s a whistleblower,” said Thomas Drake, whom the Obama administration tried to imprison spy charges for proesting a billion dollars in waste to a reporter. “I consider it a magnificent act of civil disobedience,” Drake said of Snowden, who documented for Guadian and Washington Post reporters massive surveillance of the American public in violation of the NSA's onetime requirement to focus on foreign threats.

Predictably, high federal officials called for Snowden's arrest. Also, supporters of the surveillance state warned that his actions threatened security.

National Intelligence Director James Clapper said the Justice Department should arrest Snowden, who travelled to Hong Kong to announce his role in the video, released June 9.

“The government is not going to hold back on this case,” commented Michael Vatis, a former Clinton Justice Department official. “This is a huge one.”

Greenwald is the Guardian columnist who broke the Snowden stories after working with Poitras on the probe since February. He pushed back against anti-Snowden arguments June 10 from MSNBC “Morning Joe” co-host Mika Brzezinski. Greenwald, right, said the public should be made aware of massive government surveillance to decide if they approve it. The hostess asked him to put the programs into perspective this way:

“Isn't it the case that reviewing of emails or any wiretapping cannot take place without an additional warrant from a judge and a review?” she asked. “I mean it's not like there's haphazard probing into all of our personal emails. Can we put this into context so we understand exactly what is going on?”

“Yeah, I'll put this into context for you,” Greenwald responded. “The White House talking points that you're using are completely misleading and false.”