2006: Snowden is hired by the Central Intelligence Agency as a technical expert. He is given top secret clearance.
2007-09: Snowden is posted to Geneva, Switzerland, under diplomatic cover as an IT and cybersecurity expert for the CIA, a position that gives him access to a wide range of classified documents.
Late 2009-March 2012: Snowden’s supervisor at the CIA places a critical assessment of Snowden’s behavior and work habits in his personnel file, expressing suspicion that he tried to “break into classified computer files that he was not authorized to access”. Snowden leaves the CIA and begins working as an NSA contractor assigned to Dell, one of 854,000 top-secret clearance contractors working for the federal government. Over the next several years, he switches between NSA and CIA assignments for Dell, including a stint at an NSA facility in Japan that lasts until March 2012.
March 2012 – Snowden moves to Hawaii to work at an NSA facility as a Dell employee.
December 1, 2012: Snowden contacts Glenn Greenwald, a lawyer and columnist for the British newspaper The Guardian.
January 2013: Snowden contacts Laura Poitras, a documentary filmmaker.
March 2013: Looking for a new contractor job at the Booz Allen Hamilton consulting firm at the same NSA facility in Hawaii.
May 2013: Snowden begins sending documents to Poitras, Greenwald and Barton Gellman of The Washington Post.
June 5, 2013: The first revelations to emerge from the documents provided by Snowden are published in The Guardian article about the NSA’s collection of home phone and email metadata from communication technology company Verizon as part of what is later revealed to be an even larger collection effort.
June 6, 2013 – The Guardian and The Washington Post publish an article about the NSA’s Prism program, which forces the largest US internet companies to hand over data on home users.
June 8, 2013 – The Guardian publishes NSA slides on the Boundless Informant data extraction tool, showing that the NSA collected nearly 3 billion pieces of intelligence in the US in February 2013 alone.
June 9, 2013: The Guardian reveals that Snowden is the source of the NSA leaks.
June 11, 2013: The European Union demands US assurances that newly revealed surveillance programs do not infringe on the rights of Europeans. Snowden is fired by Booz Allen Hamilton.
June 14, 2013 – The US Department of Justice charges Snowden with theft, unauthorized communication of national defense information, and deliberate communication of classified communications intelligence information to an unauthorized person.
June 23, 2013: Snowden leaves Hong Kong for Ecuador, with a planned stopover in Russia. He is stranded at Moscow’s Sheremetyevo International Airport after US authorities revoked his passport. He spends the next month living in limbo in the airport’s transit center.
August 1, 2013: Russian authorities grant him temporary asylum while they consider his application for permanent political asylum.
October 2, 2013: At a US Senate hearing on the Foreign Intelligence Surveillance Act, Director of National Intelligence James Clapper tells lawmakers Snowden’s leaks have helped enemies of the US and caused great damage to its allies.
October 14, 2013: The Washington Post reports that the NSA collects more than 250 million email inbox hits and contact lists each year from online services like Yahoo, Gmail, and Facebook. Documents are provided by Snowden.
December 16, 2013 – US District Judge Richard Leon rules that the NSA’s collection of data on all phone calls made in the US appears to violate the Constitution’s protection against unreasonable searches. But Leon, appointed by former President George W. Bush, stays his ruling to allow the government to appeal.
December 17, 2013 – Snowden publishes an open letter to Brazil offering to help investigate US surveillance of Brazilian citizens.
February 7, 2014: Based on Snowden’s documents, NBC News reports that British spies have developed “dirty tricks” to use against nations, hackers, terrorist groups, suspected criminals and arms dealers including the release of computer viruses, spying on journalists and diplomats, jamming phones and computers, and using sex to lure targets into “honey traps.”