Cade Metz and Kashmir Hill write: “When tech companies created the facial recognition systems that are rapidly remaking government surveillance and chipping away at personal privacy, they may have received help from an unexpected source: your face. Companies, universities and government labs have used millions of images collected from a hodgepodge of online sources to develop the technology. Now, researchers have built an online tool, Exposing.AI, that lets people search many of these image collections for their old photos.”