Surveillance companies, using networks of cheap Web-connected cameras and powerful new video-analysis software, are demonstrating the kind of surveillance capabilities that were once only possible in a Hollywood movie. Faces and license plates can now be spotted, in almost real time, at ports, military bases and companies. Security perimeters can be changed or strengthened with a mouse click. Feeds from hundreds of cameras can be combined into a single desktop view. And videotape that used to take hours, even days, to scour is searched in minutes.