Cellphone tracking: What happens when our smartphones can predict our every move?

A team of British researchers has developed an algorithm that uses tracking data on people’s phones to predict where they’ll be in 24 hours. The average error: just 20 meters.

That’s far more accurate than past studies that have tried to predict people’s movements. Studies have shown that most people follow fairly consistent patterns over time, but traditional prediction algorithms have no way of accounting for breaks in the routine.

The researchers solved that problem by combining tracking data from individual participants’ phones with tracking data from their friends—i.e., other people in their mobile phonebooks. By looking at how an individual’s movements correlate with those of people they know, the team’s algorithm is able to guess when she might be headed, say, downtown for a show on a Sunday afternoon rather than staying uptown for lunch as usual.

Now imagine what Facebook must be capable of knowing about you. (via)