Greg Miller of The Washington Post described the book as the first single-book account of Edward Snowden's 2013 leaking of National Security Agency (NSA) documents.

However, Miller commented that the "British perspective" of the book "overlooks some significant U.S. developments and underplays important work done by other journalists, including Barton Gellman of The Washington Post.

"[2] Greg Miller concluded that "Harding has delivered a clearly written and captivating account of the Snowden leaks and their aftermath, succeeding beyond his most basic ambition, which was to arrive in bookstores first.

"[5] Conversely, The Daily Telegraph's David Blair wrote: "Harding's story crackles with verve, but complexity and nuance are banished.

The Financial Times has since amended the article stating: "Harding insists that when he spoke to Greenwald in Rio, he made it very clear he was doing research for his book on Snowden.