alt Hacker NewsPrivate networks are not that much of a savior... It is incredibly easy to bridge networks intentionally or unintentionally. Stuxnet is just one example. Even private networks have to be as completely secure as a public one. Worse because it's 'private' people think it needs less internal security because "Why secure it, no one can get to it".
The military's approach to that problem is to use color-coded cables and ports, and we already use things like 802.1x to prevent unauthorized devices from being attached to corporate networks. This is not a novel or unsolvable problem.