Back in the day
i had a job running a large SCADA system. It controlled multiple remote sites. We were an electric utility, we had to control the various substations from System Control, 24/7. It was very secure, mostly by accident. We used Harris H800 24-bit (you read that correctly, 24-bit, they only cost half a million each...) supermini computers and communicated to the substations using powerline carrier over transmission lines. If anyone wanted to hack us, they had to either get into computer room at System Control, past the locked door. The locked doors, actually, the door to the computer room was locked and the door to building was locked. We had crashbars on the doors, you could always get out, but to get in either you had a key or someone inside IDed you using the camera outside the door and buzzed you in. And there was an armed guard at the gate to the property. We had _great_ physical security. Or they had to climb a utility pole and play with 138,000 volts at 100 to 200 amps. Good luck with that. None of our signals went over PSTN. A would-be hacker _could_ break into a substation (climb the fence or get a copy of the substation gate key and then break into the substation's control room... and he'd have control of that substation, nothing more. If he could figure out how to send the correct commands. If he survived playing with multiple 138 and 24 kV systems. And System Control would spot the problem almost immediately and send some linemen out to have a look.
I suppose that it was security by obscurity, but 138 kV at 100 amps makes for excellent security. Our heroes here might well have been able to pwn the system, if only they could touch it without being fried.
It'd have been different if we were dealing with something less rambunctious than 138 kV, but no, we were hackproof. The boys who ran the main computer system at company HQ, now, _they_ could be hacked. And were. There was a reason why we didn't let those bozos near our system. My fav example was the time that a quarter million worth of truck tires vanished from the Stores inventory. It was pretty clear who had liberated them, but as there was no record of their ever having been company property, not any more, there wasn't much which could be done. At least not up until the time I left the company, about two years later.
Biting the hand that feeds IT
