Jeff Fischbach is a little bit like those guys in The Matrix — when he puts on his shades and looks at the world, he sees data.
Walking down the street in San Francisco, he points out all the devices that record people's comings and goings: digital parking meters, apartment intercom systems, digital security cameras.
"Anything with a computer is going to keep a log," Fischbach says.
Fischbach is a forensic technologist. Lawyers eagerly pay for his ability to extract evidence from everyday devices — he's even checked alibis on kitchen appliances. But when it comes to tracking where people go, he says, the most common source of data is in your pocket."Cell phones leave a data trail," he says. "And it's becoming standard for major police departments and the feds to use this data."