This plugged machine reminds me of an interest case I saw on a fairly old semi-submersible drilling rig.
The case was presented to me with a picture of a "coffee room" with an multiple socket extension lead on top of the table and a few things connected to it such as a toaster or a kettle and there were a couple more things to the point that you always had one plug less to connect everything.
Everyone would highlight that it looked like a ****hole, the use of extensions should be avoided, extensions with power should definitely be avoided and so on...
The real problem was that the stability and ballast system was connected with a plug to that extension socket. On a bad day, making a cup of tea could kill them all.
On a similar note about plugged equipment, again on ships, some equipment like GPS units, recorders and what not are plugged appliances. For safety, they'll be powered from UPS power. One ship I worked on removed the recorder from the bridge to the captain's office and left that plug available in the wall.
The weekly cleaner came in and plugged in his vacuum cleaner in it... The UPS didn't like it and threw a fit causing all sorts of errors. (Yes, the socket should have better protection) but it's yet another case of plug equipment causing trouble.