1. The personal computer-based home security system implemented as a software program that runs on commercially available personal computers that include a modem, a microphone, and a video camera, the personal computer-based home security system monitoring an environment to detect and remedy unusual circumstances that occur in the environment, the personal computer-based home security system comprising: a monitoring component configured to sample data collected by the microphone and video camera to detect, without human assistance, threshold events that represent a change in the environment based on the sampled data; a close surveillance component that is launched by the personal computer-based home security system following the detection of a threshold event by the monitoring component, the close surveillance component more frequently sampling data collected by the microphone and video camera in order to detect, characterize, and record events that represent differences between the sampled data and data normally collected from the environment; and a remedy component that is launched by the personal computer-based home security when the close surveillance component has detected sufficient events to initiate an appropriate remedial action.