Modern facilities (such as corporate headquarters) are marvels of engineering. These buildings employ numerous embedded and software systems to help ensure convenience, business efficiency, and even security. The door that unlocks after you swipe your badge is managed by an access control system. The lights and energy flowing to your building are managed by an energy management system. The HVAC systems that keep your data center cool is controlled by an environmental control system. These invisible embedded and software systems make modern life in the corporate facility efficient, convenient, and comfortable. Given the importance and of these systems, how do we secure a modern smart building? What about a corporate campus full of thousands of automation systems? Lets take a look how building automation systems are hacked and explore approaches to secure building automation systems at scale.