ADT Security Systems. An ADT home security system installed in your home is linked to a network of five monitoring systems nationwide. These stations keep track of your system around the clock, every day of the year. If there's an intrusion, they make sure it's valid, then notify you and your local authorities of the incident. Response is fast, efficient, and personal, with real people staffing each security center. Over seven million homes in the United States alone are currently protected by ADT, as well as more than a hundred airports and fifty percent of banks. Fifteen million homes worldwide bear the ADT sticker, and provide protection for families and belongings. Additional features, like medical protection and breaking glass sensors, add even more protection and peace of mind for you and your family. If your home isn't protected against break-ins, fire, and more, it's time to contact ADT.