I am shocked,” said Martin Schulz, president of the European parliament, in response to leaks revealing US surveillance of EU figures. There are faint echoes of Captain Renault in the film Casablanca , who professed to be “shocked – shocked!” to discover gambling in a gambling den.

This indignation at American spying has a ritual and contrived element. Espionage, including espionage between allied states, is nothing new. It is also entirely mutual, as Barack Obama, the US president, implied in his first public reaction. After the obligatory protestations – the Americans did commit the cardinal sin of getting caught – this latest episode might blow over, as has happened after previous exposures of “friendly spying”. But this situation is new.

Traditionally, spying is akin to spearfishing; specific information is sought, individuals acting for particular organisations are targeted. But US espionage has gone industrial: an ever-wider net is cast over whole populations in the expectation that something will found. In Germany, a country of 80m people, 15m to 60m separate communications connections are scanned every day by the US National Security Agency – evoking invidious (and unfair) comparisons with the East German experience of life under Stasi surveillance.