(Bloomberg) -- Edward Snowden caused “tremendous damage to national security” by revealing “secrets that protect American troops overseas and secrets that provide vital defenses against terrorists and nation-states,” according to a new congressional report.
“The U.S. government has spent hundreds of millions of dollars, and will eventually spend billions, to attempt to mitigate the damage Snowden caused,” the House Intelligence Committee said in an unclassified summary of its 36-page report.
The material leaked three years ago by Snowden gave unprecedented insight into the inner workings of a clandestine spying operation that tracked phone calls and e-mails globally. His leak set the stage for fights that continue between the U.S. government and technology companies including Apple Inc.
The committee said Snowden stole more than 1.5 million classified documents and questioned his motives, saying that two weeks before “he began mass downloads of classified documents, he was reprimanded after engaging in a workplace spat” with managers at the National Security Agency, where he worked as a contractor.
The report was released as a movie sympathetic to Snowden from director Oliver Stone debuts in theaters and as supporters who consider Snowden a whistle-blower who exposed government invasions of privacy campaign for him to receive a presidential pardon.
Snowden, now a fugitive living in Russia, began releasing classified material in 2013, causing an international backlash against the U.S. and heightening tensions between President Barack Obama and other world leaders who protested that they or their citizens had been spied upon.
The coalition calling for Snowden’s pardon includes Apple co-founder Steve Wozniak, billionaire George Soros, actors Maggie Gyllenhaal and Daniel Radcliffe, and groups such as the American Civil Liberties Union.
“Thanks to Edward Snowden’s act of conscience, we have made historic strides in our fight for surveillance reform and improved cybersecurity,” said ACLU executive director Anthony Romero.
All members of the House Intelligence Committee, from both parties, signed a letter Thursday urging Obama not to pardon Snowden.
Snowden, 33, worked for NSA contractor Booz Allen Hamilton Holding Corp. and used his credentials as a systems administrator to copy voluminous data from sensitive systems. He has been charged with espionage and theft by the U.S. Justice Department.
White House spokesman Josh Earnest told reporters Wednesday that the administration’s position remains unchanged: that Snowden should return to the U.S. and face “the very serious charges” against him.
To take classified information, Snowden obtained the security credentials of some of his co-workers through misleading means, searched their computers, and removed personal information related to thousands of intelligence agency employees and contractors, the committee said in its report, which didn’t provide any examples or evidence of actual damage his leaks caused.
Although more than three years have passed, the NSA and other intelligence agencies still haven’t implemented needed security improvements to prevent another major breach, the panel said.
Snowden’s revelations continue to reverberate, having a direct and long-term impact on governments, corporations and consumers around the world.
Companies including Apple began providing customers with strong encryption as a matter of course, a move that law enforcement agencies say impedes their ability to investigate terrorists and criminals.
Tensions peaked in February when the FBI served Apple with a warrant trying to force the company to hack into an iPhone used by Syed Rizwan Farook, who along with his wife carried out a mass shooting in San Bernardino, California. Apple refused and the FBI backed down after saying it found another way to get into the phone.
Snowden exposed programs under which the NSA intercepted e-mails and other communications from internet companies, collects phone call records on millions of people not suspected of wrongdoing, and hacked into fiber-optic cables abroad to covertly obtain information from Google Inc. and Yahoo! Inc.
In addition to the government asking internet companies to turn over data about their users, the documents leaked by Snowden revealed that the U.S. physically intercepted routers, servers and other network equipment in order to install surveillance tools before they were shipped to users.
Documents also showed that the NSA acted to weaken standards used to encrypt and protect data, and possibly infected millions of computers globally with malware.
Facing mounting criticism about overreach by intelligence agencies, Obama signed a law in June 2015 prohibiting the NSA from collecting bulk phone records, including information about phone calls made by millions of Americans who aren’t suspected of having links to terrorism.
The law, which requires the government to request such information from telecommunications companies, put an end to one of the first spy programs Snowden exposed and has been hailed as one of the most significant reforms made to curb U.S. spying.