So in my first job, I was put onto doing the programming for a completely programmable video display - so programmable you had to have a program loaded into its rom for it to do anything. And one of the things they did was decided to have a removable keyboard.
Obviously a terminal without a keyboard is going to be hard to enter data on. So, I made the code able to detect various conditions including keyboard being removed/added. On removal it flashed up on the top line "give my keyboard back, you thieving basket" and then replaced that message with "thank you" when a keyboard was detected, which message went away after a short while.
This was apparently so impressive it got demonstrated to customers as a feature of our system. and it was several years before someone complained about the content of the message!