1. A method of video surveillance, comprising: receiving, by a computer system, video images from a video sensor the computer system performing the steps of: analyzing the video to detect stationary objects in the video using background subtraction of a background model; analyzing the video to detect people in the video using frame differencing and tracking to detect moving objects; upon detecting a first stationary object in the video, defining a zone as a portion of the video around the first stationary object, defining the zone being responsive to a location of the first stationary object, the zone being defined to be larger than an outer boundary of the first stationary object and smaller than a field of view of the video; analyzing the video to determine a distance between another stationary object and a person putting down the another stationary object; wherein the size of the zone is responsive to the analyzing of the video to determine the distance between the another stationary object and the person putting down the another stationary object; tracking a duration that the first stationary object remains stationary; and issuing an alert in response to determining that the duration of time the first stationary object has remained stationary exceeds a threshold while no person of interest detected in the video has been inside the zone.