> In all fairness, the people who are experts in the field of Siemens PLC programming are usually mechanical-ish engineers and security is not in their skill set or on their mind.

Stuxnet was over a decade ago.

There should be a simple rule that everyone with the ability to understand things like PLCs should be able to grasp: your equipment does not touch the internet or external storage, period.

Those who can't grasp this concept should be shown the door with a recommendation that they find a less mentally-taxing line of work.