It's also a sad fact of life that pilots don't always read Notams and AIC's etc. I have plenty of experience of the professionals trying to blow workmen over on airfields, totally oblivious of WIP
I was in a rear seat recently going down the severn estuary when it became apparent that the persons upfront - which included an instructor, were not aware of the exclusions around our power stations.
However, it strikes me that an air exclusion zone without the teeth to enforce it is a bit like...........
So how do we protect these installations if we value them or believe them to be serious targets?