It examines the history of digital surveillance and code-breaking, and how it has transformed into modern cyberwarfare.

Richard Norton-Taylor writing in The Guardian felt that "If you are looking for a clear and comprehensive guide to how communications have been intercepted, from cable-cutting in the First World War to bulk data collection exposed by Ed Snowden, this is it ... A most readable account of how computers and the internet have transformed spying".

Ed Vulliamy in The Observer noted that the book "takes us through the labyrinth of cyber-espionage ...

[3] In The Sunday Times Stephen Dorril described Cyberspies as "Riveting ... Making use of excellent sources...[Corera] has produced a highly relevant read that addresses the key debate in intelligence gathering - the balance between privacy and security".

The result is an informative, balanced and revealing survey of the field in which, I suspect, most experts will find something new" and The Economist wrote of the book's conclusion that "The true golden age of spying and surveillance - whether carried out by states or, increasingly, by companies - is now".