British artist James Bridle is fascinated by surveillance technology. Once, he photographed more than 200 CCTV cameras on the walk between his London flat and the tube. This past year, he installed a white surveillance balloon above an abandoned East London parking lot. So it made sense that when Bridle was asked to host an online artist’s residency, he planned a 12-mile stroll around London’s central district to take stock of all the cameras that analyze car license plates.