[momotomo]

Second this, as per other comment I made as well. SCADA systems are generally unstable and very precious about how they are implemented, it can drive people to make a lot of concessions. Thankfully we run enough support staff to ensure physical site visits are possible, which eliminates the security and technical issues associated with trying to tie these things into a WAN.

*edit, inferring that instability can drive people to network these devices for support reasons.