It looks like a network security/competency test question.

There's a simple solution: require mobile phone manufacturers to degrade handset functionality when the GPS unit detects the handset is moving beyond a certain threshold, ie 10mph. This "inMotion" boolean could be used to disable handset access to text messing or dialing of non-emergency (911) numbers. In smartphones it also could be used in combination with a "mobileAllowed" boolean to prevent a web browser from being used but still allow access to applications such as maps. If the FCC added this requirement to their certification process, all handsets would require this functionality or they could not be sold within the USA. Mobile phone manufacturers need to take a lesson from vehicle manufacturers - many in-car navigation or "infotainment" systems are already limiting access to some features while the vehicle is in motion. This type of implementation would disable access to some features while individuals travel on public transportation, which wouldn't be ideal. I supposed a work-around to re-enable the functionality while in motion could be the use of a Bluetooth or WiFi beacon that indicates full-functionality while inmotion is allowed. If Bluetooth headsets can be sold for $10, I'm sure something like this could be manufactured inexpensively and sold to authorized clients.

There are many different types of SCADA implementations and several options for remotely accessing them - RF (VHF or UHF radio telemetry), cellular, network (wired, or wireless bridged), etc. The answer is simple - if a disaster would result from unauthorized access you need to find a consultant that knows enough about the implementation to keep the bad guys out. Spend the money and get it done right. I've often wondered about some of the SCADA implementations over VHF or UHF radio telemetry and what the person was thinking when the system was put into place, that's as insecure as a CB radio and probably controls some critical infrastructure that people depend on. This whole topic is going to keep resurfacing for years to come, and recent events such as Stuxnet proved this is an area to be concerned with.