ADT Security Services is a unit of Tyco International and part of ADT Worldwide, the world’s largest electronic security provider. In North America, ADT provides electronic security services to nearly five million commercial, government and residential customers. ADT's total security solutions include intrusion, fire protection, video systems, access control, critical condition monitoring, home he...alth services, electronic article surveillance, radio frequency identification (RFID) and integrated systems. ADT’s government and commercial customers include a majority of the nation’s Fortune 500 companies, all U.S. federal courthouses and over 70 mid to large airports. Headquartered in Boca Raton, Florida, ADT has more than 24,000 employees at approximately 240 locations in the U.S. and Canada.