Security alarm

A security alarm is a system designed to detect intrusion – unauthorized entry – into a building or other area. Security alarms are used in residential, commercial, industrial, and military properties for protection against burglary (theft) or property damage, as well as personal protection against intruders. Security alarms in residential areas show a correlation with decreased theft.[1] Car alarms likewise help protect vehicles and their contents. Prisons also use security systems for control of inmates.

Quotes

 * There's gonna be a lot of slow singing and flower bringing if my burglar alarm starts ringing.
 * Christopher Wallace, "Warning"