We actually don't know how much he handed to them but he stole 1.5 million classified documents when he fled. According to: https://intelligence.house.gov/uplo

We actually don't know how much he handed to them but he stole 1.5 million classified documents when he fled. According to: https://intelligence.house.gov/uploadedfiles/hpsci_snowden_review_declassified.pdf https://intelligence.house.gov/uploadedfiles/hpsci_snowden_r... > Since Snowden’s arrival in Moscow, he has had, and continues to have, contact with Russian intelligence services., and in June 2016, the deputy chairman of the Russian parliament’s defense and security committee asserted that “Snowden did share intelligence” with his government.' > Over the past three years, the Intelligence Community and the Department of Defense (DoD) have carried out separate reviews—with differing methodologies—of the contents of all 1.5 million documents Snowden removed. It is not clear which of the documents Snowden removed are in the hands of a foreign government. The US govt is assuming they have it all > Out of an abundance of caution, DoD therefore reviewed all 1.5 million documents to determine the maximum extent of the possible damage.