"Researchers …have come up with an algorithm that follows your own mobility patterns and adjusts for anomalies by factoring in the patterns of people in your social group (defined as people who are mutual contacts on each other’s smartphones).
The method is remarkably accurate. In a study on 200 people willing to be tracked, the system was, on average, less than 20 meters off when it predicted where any given person would be 24 hours later."
Full article TechnologyReview
Via: Mark Pesce