The inverse - 20 A plug to 15 A socket - would be perfectly fine and conform to code, you couldn't possibly pull an overcurrent that the breaker might fail to d

The inverse - 20 A plug to 15 A socket - would be perfectly fine and conform to code, you couldn't possibly pull an overcurrent that the breaker might fail to detect. What's really scary is that in many commercial buildings you have combined 5-15/5-20 sockets (this sort:https://en.wikipedia.org/wiki/NEMA_connector#/media/File:Electrical_outlet_with_label.jpg https://en.wikipedia.org/wiki/NEMA_connector#/media/File:Ele...) for circuits fused to 20 A. If you had rigged your locking to non-locking adapter with a 5-20 plug you'd again be fully code-compliant. Look at the background of two photos! The shelving would indicate the offensive thing was found in a datacenter, it must have been a semipermanent hack, not something that someone might use in their office with the door locked and curtains drawn to set up equipment and otherwise keeps in a locked drawer.