From somebody who has actually worried about such anachronisms as air gapped networks, I can tell you that in a lot of secure environments usb and ieee io was a

From somebody who has actually worried about such anachronisms as air gapped networks, I can tell you that in a lot of secure environments usb and ieee io was actually physically disconnected. This has taken a pretty hard hit recently, as many many systems no longer ship with DIN connectors for keyboard and mouse. For a variety of reasons it's much easier to lock down the available drivers in the os than to try to keep sourcing systems that can operate entirely without usb. And even that was rather difficult under windows until recently. I don't have a real wrapped up conclusion here, except to say that if these quite security conscious organizations that pay close attention to these issues have found it a pain to implement IO restricted general desk PC's, it's no wonder at all that most private organizations are having trouble.