Video surveillance cameras are used extensively.  Usage of video cameras in residential environments has increased substantially, in part due to lower prices and simplicity of deployment.  In many cases, surveillance cameras include infrared emitters in order to illuminate a scene when light from other sources is limited or absent. 
Some video cameras enable a user to identify “zones” within the scene that is visible to the camera.  This can be useful to identify movement or changes within those zones. 
Because a surveillance camera can capture a very large amount of data (e.g., running 24 hours a day, 7 days a week), some cameras enable a user to set up alerts based on specific criteria.  The criteria can include movement within a scene, movement of a specific type, or movement within a certain time range.