Amazon unveiled a new tracking system at a time when Americans are debating the value of persistent surveillance.

New Orleans, home of Bourbon Street revelry, has become the first American city known to have a live facial recognition network. How that came to be is a story of private initiative and political ...

Humans have excellent gaze detection. We know instinctively when another person is staring our way. But unless a camera is particularly conspicuous, like the creepy "human-eyeball" webcam created by ...

Add Yahoo as a preferred source to see more of our stories on Google. Sandy Boyce of Sedona, Arizona (Matt Martian for NBC News ) Sandy Boyce, a 72-year-old retiree in Sedona, Arizona, first saw the ...