I've heard a lot of stories regarding security and physical separation. The most funny was a repair guy from IBM or Cray in the 80ies or 90ies was tasked to re

I've heard a lot of stories regarding security and physical separation. The most funny was a repair guy from IBM or Cray in the 80ies or 90ies was tasked to repair a broken storage array in a super calculator doing some sensitive computation. He expected one of the disks to be dead (at the time those were quite expensive) and brought a new one. He plugged it and it was not that, the array was still KO. In the end it was a broken (and much cheaper) controller card. So he fixed it, and starting to going home. But the guards didn't let him go back with the expensive spare drive and the brand new drive had to be destroyed. There was some conflicts after that on whether or not the destroyed drive was part of the maintenance contract and who should pay for it (the government agency or the company doing the support and maintenance).