The dream—or nightmare—of near-flawless surveillance is on us, and it is starting to change our lives in ways few of us could have imagined. Companies that parse location data emitted by our cell phones can now accurately predict where each of us will be at any point during the day. They can also figure out from phone records who our friends, family and co-workers are, when we are likely to get the flu, and what the demographics of any major metropolitan street corner will be at any moment.
The key to this explosion of data is smartphone penetration, which surpassed 50 percent in the U.S. this year. Nearly every one of those devices, by default, sends a steady stream of location data back to centralized servers because few users bother to opt out of such data collection or are even aware that they can. Scientists and commercial researchers are figuring out how to plow through the billions of coordinates, enough to chart the movements of millions of people.
This article was originally published with the title World Changing Ideas.