Abstract: Disclosed is a security and alarm system. When sensors detect something of note, they alert a master unit which in turn captures pertinent information (e.g., an image or sound) and places a mobile-telephone call to deliver the alert and the captured information. The recipient of the call (for example, an owner of the system or a security service) evaluates the information and takes appropriate action such as alerting a local police department. Some embodiments offer two-way service: In addition to delivering alerts, the system responds to calls from an authorized user requesting current information. Two-way communications allow some embodiments to deliver “Breach of Peace” alerts to users. In one scenario, a public security service sends out a warning within a geographical area that the peace has been breached. The system receives the warning and alerts its user to the situation. The user then takes appropriate action.