Currently, G4S employs more than 620,000 people, which makes it the third biggest employer in the private sector globally. In 2012 G4S turned over well over $12 billion. The company offers a range of services, including the supply of security personnel, monitoring equipment, response units and secure prisoner transportation. G4S also works with governments overseas to deliver security. The revolution brought on by wireless technologies, smart phones, and mobile apps have changed all of that. Today, home security systems can still sound alarms, but are much more difficult to forget about or foil. A software supported security system can send you a text message every time a door or window is opened, whether you’ve armed it or not. It can stream live video or send still images of what’s happening in your garage, living room, backyard or wherever you deploy a security camera. You can even be alerted before the break in, the moment the burglar pulls into the driveway!BUILDING A SECURITY SYSTEM Smart systems consist of hardware that doesn’t look a lot different than it did twenty five years ago. There are some specialized sensors and video cameras that weren’t common in the past and window and door contact switches have gotten a lot smaller, but the basics are the same: a control panel or console, magnetic contact switches, motion sensors, a siren. The new systems may also be connected to central monitoring stations, as do many old style security systems.