A system of user detection includes a camera configured to rotate to a plurality of positions, a memory that stores a module, and a processor coupled, locally or remotely, to the camera. The processor is configured to send a command to the camera to cause the camera to (1) rotate to a position from the plurality of positions, and (2) capture a photo or a video clip at the position. The processor is configured to receive the photo or the video clip from the camera; determine whether a user is captured in the photo or the video clip; divide the photo or the video clip into a plurality of zones; determine a zone from the plurality of zones where the user appears in the photo or the video clip; and determine whether the user is associated with a device based on information of the position and the zone.