The latest revelations about the NSA's surveillance plans are perhaps the most shocking yet: Documents leaked via Edward Snowden allege the agency is tracking the position and movements of what the New York Times calls "hundreds of millions of cellphones outside the United States" so its algorithms can find give-away travel patterns or meetings or group discussions of "intelligence targets."
The allegations come with the assertion that the agency doesn't target U.S. citizens' phones inside the country. But if we assume that, of the 7.1 billion people alive, we discount 0.3 billion people in the U.S. and another billion for the few world citizens who don't have cellphones and to compensate for people who have two or more cellphones, then assume the "hundreds" of millions of phones surveilled is between 200 million and 500 million... the raw figures suggest the NSA could be tracking anywhere from 4% to 9% of all the people in the world on a daily basis. That figure is the one that may shock you.
Location tracking on a voluntary basis is a fast-growing technology, and is inherently a part of the way some navigation systems like A-GPS work. Consumer tech giants like Google and Apple have faced public and political criticism in the U.S. for tracking their users' locations.