Anecdotally,
Circa the mid 90s, I took a support call from a chap who was complaining that his computer wouldn’t turn off. This was in the days before the proliferation of the soft-power ATX form factor; power was controlled by a proper mechanical switch which made / broke the 240V supply. Beyond “faulty switch” the only think I could think that would cause this was user error; he’s pressing the wrong button or something.
In the course of diagnosing what was going on, he happened to mention in passing that his new computer was also supplied with a cable missing. And then the whole tale unravelled.
AT-style power supplies commonly came with a socket for the ubiquitous “kettle lead” connector that we all know and love, along with a female outlet so that you could piggy-back the monitor power off the same PSU rather than running it directly from the mains. Switch off your PC, and it isolates the power output to the monitor as well.
We’d evidently sent out a PC with a regular mains cable for the computer, and an identical mains lead for the monitor, just like you’d typically get today. Our hero had seen the two sockets on the computer and gone “hmm, that’s odd.” So he’d tried to get a cable to fit the unused outlet. To his astonishment, they were really difficult to source.
Ever resourceful, in the end he’d had a cable custom made, with a 13A UK mains plug on one end, and a male C14 inlet socket on the other. He’d plugged in both power leads; the regular female one into the PC’s Power In, and his bastard cable into its Power Out, both connecting back to the mains supply. And, rejoice, it all worked! Except he couldn’t switch his PC off because, y’know, it was supplying 240V to the power OUTLET which was on the other side of the isolating switch. 😯
At which point, he then rang support.
Of course, it was a monumentally dangerous thing to do. The cable would’ve had exposed pins, there’s nothing to stop him plugging it into the mains and sticking some appendage in the other end with hilarious disastrous results. God only knows who he’d got to make up such a thing.
People.