But in reality, why’s that a problem? Is the credit card scanner so tacitly busted that it can’t coexist with other hosts? Does it not use TLS? Doesn’t it pin TLS certs so that it’s not subject to MITM? Is it listening on ports with vulnerable services? There’s no excuse for the scanner being that delicate. It should be able to service an office LAN. And yet, the PCI-DSS group managed to push the responsibility for their hardware onto the network owners rather than making their own hardware robust. That’s nuts.