A new video from human rights organization Amnesty International maps the locations of more than 15,000 cameras used by the New York Police Department, both for routine surveillance and in facial-recognition searches. A 3D model shows the 200-meter range of a camera, part of a sweeping dragnet capturing the unwitting movements of nearly half of the city's residents, putting them at risk for misidentification. The group says it is the first to map the locations of that many cameras in the city. Amnesty International and a team of volunteer researchers mapped cameras that can feed NYPD's much criticized facial-recognition systems in three of the city's five boroughs--Manhattan, Brooklyn, and the Bronx--finding 15,280 in total. Brooklyn is the most surveilled, with over 8,000 cameras.

That clunky old Android phone sitting in a drawer may be more useful than you think. A team from Carnegie Mellon University has created a program called Zensors that uses connected smartphone or surveillance cameras to track your environment, figure out what's going on and give you valuable alerts and statistics. The team showed how a user can point a smartphone outside a window, circle an area of interest, and pose a natural-language question like "how many cars are in the parking lot?" Zensor then proceeds to track cars as they enter and leave, giving a business data about its customers. Such tasks are way beyond the means of regular smart home cameras and sensors, but the tech isn't quite as magical as it sounds. The researchers are relying on crowd-sourced workers to for complex tasks like counting cars, while easier tasks are calculated by algorithms.