Spying may be the world’s second-oldest profession, but espionage has been quick to embrace the technology of the internet era. Just as the online economy has made it easier to buy and sell goods and services, so the net is making it easier to steal and trade information. And companies are just as likely to be the targets of espionage attempts as government agencies.

“By no means do nation states have a monopoly on espionage,” says Ed Parsons, a senior manager in the UK cyber security practice at KPMG. “We are seeing for-profit and mercenary groups, stealing information and trying to sell it, including to governments.”

Mr Parsons says that one reason cyber espionage is growing is because blame is hard to apportion. Unlike the characters of John Le Carre’s cold war-era novels, who risked arrest or worse, today’s cyber spies are hard to trace and easy for governments and others to deny knowledge of.