A scathing report by the House Intelligence Committee, backed by liberal Democrats and conservative Republicans, concludes that Edward Snowden was a disgruntled, serial liar who leaked for petty reasons, put American soldiers at risk and remains in continuing contact with Russian intelligence services.
The 37-page review, filled with redactions of classified material, does not accuse Snowden of being a spy, but it seeks to poke holes in nearly every aspect of his account of why he gave reporters reams of classified documents he obtained as a contractor — and trusted insider — with the National Security Agency.
Snowden immediately began denouncing the report on Twitter from his home in Russia, saying its core claims were made "without evidence" and that it established nothing worse than he might have been hard to work with.
More from NBC News:
Berlin truck suspect Anis Amri's journey from troubled teen to alleged terrorist
Same Russians who hacked DNC helped Target, kill Ukrainian soldiers
Trump names campaign chief Kellyanne Conway as counselor to the President
His lawyer, Ben Wizner, told NBC News he considers the report "a failed attempt to discredit Edward Snowden, whose actions led to the most significant intelligence reforms in a generation."
"The report wholly ignores Snowden's repeated and courageous criticism of Russian surveillance and censorship laws," Wizner said. "It combines demonstrable falsehoods with deceptive inferences to paint an entirely fictional portrait of an American whistleblower."
Rep. Adam Schiff, who represents a bright blue district in California and is the ranking Democrat on the House Intelligence Committee, said the two-year review of classified documents explodes many myths advanced by Snowden supporters.
"Snowden and his defenders claim that he is a whistleblower, but he isn't," Schiff said. "Most of the material he stole had nothing to do with Americans' privacy, and its compromise has been of great value to America's adversaries and those who mean to do America harm."
The report takes direct aim at Snowden's stated motives for removing an estimated 1.5 million documents from NSA in what officials have called the most significant leak of national security information in American history.
It portrays him as a serial exaggerator and fabricator who first exaggerated the importance of his job at the CIA — where he worked before joining NSA — and then lied about having ethical qualms about it. It says he cheated on a test that got him a job with NSA's elite Tailored Access Operations office, known as TAO.
Snowden has said that his "breaking point" was Director of National Intelligence James Clapper's false statement to Congress in March 2013 that the intelligence community was not collecting millions of records on Americans. As Snowden and other NSA employees knew, that was not true — the NSA had for years been secretly gathering storing domestic calling records for use in terrorism investigations.
The report says that Snowden began downloading secrets eight months before, just a few weeks after a spat with his NSA supervisors.
One issue of contention, the report says, was a software patch Snowden installed while working at an NSA facility in Hawaii that caused servers to crash. After a manager complained in a mass email, Snowden fired back to a much more senior NSA official, leading to a rebuke that his conduct was unacceptable. He apologized — and then began unauthorized downloads of material, the report says.
The report's passage on Snowden's alleged contacts with Russian intelligence services is mostly blacked out, but it quotes the deputy chairman of a Russian defense committee in parliament, who said in June that Snowden did share information with Russian intelligence.
On Twitter, Snowden pointed out that the Russian politician also said he was speculating. But the near-universal view across the U.S. intelligence community is that the Russians have access to much of what Snowden obtained.
Snowden has consistently denied cooperating with Russian intelligence. In 2014, he told NBC News during an exclusive U.S. broadcast interview that he had "no relationship with the Russian government at all" and was not a spy. He told Yahoo News he gave the Russians "the stiff arm."
In terms of damage, the report says the Pentagon identified eight "high risk issues" stemming from the Snowden leaks, including information that would put troops at risk if, as U.S. officials assume, the Russian and Chinese militaries now possess it.
The report lists 21 examples of ways in which Snowden's leaks caused "massive damage" to U.S. national security. But each one is blacked out.
In arguing that Snowden cannot be considered a whistleblower, the report points out that the vast majority of what he took — most of which has never been disclosed — had nothing to do with electronic surveillance issues or privacy and civil liberties.
The report also notes that he spied on colleagues, invading their personal privacy, and that he hunted for personnel records about promotions and hiring at NSA. And it says investigators could find no evidence he ever expressed any concerns to colleagues about the nature of NSA's surveillance work.
Snowden's disclosure that the NSA had been keeping phone calling records on nearly every American led to the overhaul of that program, and some other modest changes in the rules for U.S. surveillance.
But most of his leaks had little impact on how the NSA does business. His disclosure of the so-called PRISM program, for example — under which the federal government spies on foreigners by gathering data from U.S. internet providers — did not lead to the abandonment of that program, which is considered extremely valuable even though it incidentally collects some American data.
However, the law governing that program expires next year, and some commentators have wondered whether Democrats in Congress will support extending it under President Donald Trump.
The reporting on Snowden's disclosures by the Guardian and the Washington Post won major awards, as Snowden noted on Twitter.
"Not one page mentions this journalism won the Pulitzer Prize for Public Service, reformed our laws, and changed even the President's mind," Snowden said.
Yet the report notes with irony that in 2012, Snowden met with a training officer at NSA headquarters in Fort Meade, Maryland and expressed concerns that he failed a test designed to train NSA operatives how to use the PRISM program while adhering to privacy and civil liberties standards.
"At no point during the visit did Snowden raise any concerns about how the NSA used" the program to collect internet data from American companies, the report said.
"This extensive report shows Snowden is no hero," said Rep. Lynn Westemoreland, a Georgia Republican who chairs an intelligence subccommittee that oversees NSA. "He should be brought to justice for his reckless actions."