ADT, also known as, ADT Security Services, is a unit of Tyco International. The public company provides electronic security solutions to more than 5 million commercial, government and residential customers in North America. It serves the federal courthouses, airports and various Fortune 500 companies. The company s security solutions include intrusion, fire protection, video, access control, critical condition monitoring, home health, electronic article surveillance and radio frequency identification systems. Its ADT Select DataSource solution facilitates secured access to the time and date stamps of security systems through the Web. ADT Security Services has over 24,000 employees at nearly 240 locations in the United States and Canada.