The TSA is in the early phases of exploring the technology, which Purdue University researchers tested for a month last year at Indianapolis International Airport. Thumbnail-size receivers near checkpoints detected serial numbers emitted by some electronic devices being carried by passengers. The receivers recorded the time when a passenger entered a security line and the time when the same passenger cleared the checkpoint, Purdue transportation engineer Darcy Bullock said. Only part of each serial number was recorded, and the numbers were quickly deleted, he said.The TSA says a few European airports are already using systems like this, and that London's Heathrow Airport plans to start soon. Absolutely nothing about this could possibly go wrong!
Some electronic devices automatically broadcast, or "chirp," their serial number every 15-20 seconds when they are turned on. People can set their devices so they don't broadcast. Bullock found he could detect signals from 6% to 10% of Indianapolis passengers. "We sit there and listen, capturing the unique identifier," Bullock said.
Marc Rotenberg of the Electronic Privacy Information Center said Bullock's current system minimizes privacy risk by recording partial serial numbers. But he worries that could change.
Airport device follows fliers' phones (USA Today)