The value of things changes over the years. There was a time light bulbs were valuable enough that people would steal them from hotels, public buildings, and the workplace. Below is a little artifact of that time, a 1920’s light socket with a lock. Once a bulb is screwed in, it will not come out unless you insert a key to release it.
The ad at the bottom indicates an additional bonus–people can’t unscrew the bulb to power unauthorized appliances in the workplace. Sorry, no heaters or coffeepots.