The saga of Edward Snowden and the NSA makes one thing clear: The United States' central role in developing the Internet and hosting its most powerful players has made it the global leader in the surveillance game.
Other countries, from dictatorships to democracies, are also avid snoopers, tapping into the high-capacity fiber optic cables to intercept Internet traffic, scooping their citizens' data off domestic servers, and even launching cyberattacks to win access to foreign networks.
But experts in the field say that Silicon Valley has made America a surveillance superpower, allowing its spies access to massive mountains of data being collected by the world's leading communications, social media, and online storage companies. That's on top of the United States' fiber optic infrastructure -- responsible for just under a third of the world's international Internet capacity, according to telecom research firm TeleGeography -- which allows it to act as a global postmaster, complete with the ability to peek at a big chunk of the world's messages in transit.
"The sheer power of the US infrastructure is that quite often data would be routed though the US even if it didn't make geographical sense," Joss Wright, a researcher with the Oxford Internet Institute, said in a telephone interview. "The current status quo is a huge benefit to the US."
The status quo is particularly favourable to America because online spying drills into people's private everyday lives in a way that other, more traditional forms of espionage can't match. So countries like Italy, where a culture of rampant wiretapping means that authorities regularly eavesdrop on private conversations, can't match the level of detail drawn from Internet searches or email traffic analysis.
"It's as bad as reading your diary," Wright said. Then he corrected himself: "It's FAR WORSE than reading your diary. Because you don't write everything in your diary."
Although the details of how the NSA's PRISM programme draws its data from these firms remain shrouded in secrecy, documents leaked by spy agency systems analyst Edward Snowden to the Guardian and The Washington Post newspapers said its inside track with US tech firms afforded "one of the most valuable, unique, and productive" avenues for intelligence-gathering. How much cooperation America's Internet giants are giving the government in this inside track relationship is a key unanswered question.
Whatever the case, the pool of information in American hands is vast. Redmond, Washington-based Microsoft Corp accounts for more than 90 per cent of the world's desktop computer operating systems, according to one industry estimate.
Mountain View, California-based Google Inc carries two-thirds of the world's online search traffic, analysts say. Menlo Park, California-based Facebook Inc has some 900 million users -- a figure that accounts for a third of the world's estimated 2.7 billion Internet-goers.
Electronic eavesdropping is, of course, far from an exclusively American pursuit. Many other nations pry further and with less oversight. China and Russia have long hosted intrusive surveillance regimes.
