SCADA [Supervisory Control and Data Acquisition] systems have some bigger problems than your run-of-the-mill website. These are long lived systems, not something you can just hack back together if it goes down. These are your power plants, water treatment facilities, HVAC on space systems. “Offline” is not an option. So, what to do?
See the talk here: http://www.brighttalk.com/webcast/7651/44281