hah this was such a brain weird moment, testing my usb-cereal crossover cable between new server and thinkpad, accessing both over ssh from my desktop..

and typing in one serial console seeing it show up on the other :3

@irl linking the voltage lines together would probably be a bad idea too, or what it seems like they're talking about, just directly connecting wires. This is a usb > serial > serial > usb bridge with just a shared ground so totally safe