I don't know if anyone else has noticed this but I have started to see in public places the 5-15R outlets that housekeeping would use in the hallways being either replaced with locking covers (downtown library) or L5-15R receptacles (our NHL Arena).
Janitors have a nasty habit of ripping the faces off of 5-15s , even the heaviest duty ones, by pulling sideways on the cords of their vacuum cleaners.
It's good that they converted to locking receptacles, if for no other reason.
