单选题
These days, the computerised world presents spies across the globe with both a challenge and an opportunity. Unlike the paper kind, electronic data is weightless, and computers are riddled with security holes. That makes stealing secrets easier than ever. At the same time, computers are able to place the sort of cryptography with which Bletchley Park struggled in the Second World War into the hands of everyone—including criminals, foreign spies and terrorists.
Balancing the risks and rewards can sometimes be difficult. Mr. Corera describes how Markus Wolf, the head of East Germany"s notorious Stasi, resisted the temptation to computerise his organisation"s miles of paper files. After all, pointed out Mr. Wolf, the very convenience of computerised data made a big leak more likely. That point was spectacularly illustrated in 2013, when Edward Snowden walked out of America"s National Security Agency with tens of thousands of pilfered documents, a feat that would have been impossible in the pre-computer age.
Mr. Corera has been given plenty of access to Western intelligence agencies, and he describes their dilemmas with sympathy. Monitoring the internet for suspicious behaviour may help forestall a terrorist attack, they point out, and arguments about privacy can seem abstract and unreal after such attacks succeed. At the same time he does not shy away from the implications of granting the spies ever more power to surveil. Technology has made practical the kind of mass surveillance that would have turned Mr. Wolf green with envy. In the West, at least, such powers are held in check by laws governing how the agencies behave. But the temptation to go further, to trade a little more privacy for a little more security, is always present.
At the same time, the ability to conduct such mass surveillance is no longer confined to nation-states. The Internet"s biggest companies—such as Facebook and Google—have put a corporate twist on mass surveillance. The price for their services is collecting up users" data: detailed lists of their preferences, habits, opinions and life histories, all packaged up and sold to advertisers to help them target commercial products.
The main message of Mr. Corera"s book, though, is that computers have automated espionage, and made it cheap and easy. Spying on someone used to be hard, labour-intensive work. Tails had to be set, hidden microphones planted, post intercepted and steamed open. These days a person"s laptop and smart-phone broadcasts their life across the Internet, pre-packaged into a form that other computers can digest, analyse and correlate. Never mind all those cold-war thrillers set in 1970s Berlin. The true golden age of spying and surveillance—whether carried out by states or, increasingly, by companies—is now.
单选题
The example of Edward Snowden is used to demonstrate ______.