There's a slippery slope argument here as well -- i.e. once built, the natural human desire for convenience will slowly erode security features within the syste

There's a slippery slope argument here as well -- i.e. once built, the natural human desire for convenience will slowly erode security features within the system. Imagine if someone asked for a way remotely administer a nuclear power plant over the Internet. It's possible to build a reasonably secure system -- VPN, one-time passwords, company-issued hardware, etc. But security isn't exactly intuitive to a lot of people and there are a bajillion ways to screw this up. So given the dangers involved with a nuclear power plant, the smarter approach is to simply insist that nuclear power plant control systems be air gapped from the rest of network rather than to figure out a 'good enough' way to secure remote access.