I worked at a company where everyone would try and send an email to themselves from an unlocked PC. That mail contained a heads up that the victim willl bring cake into the office e.g. next tuesday. They then were typically forwarded to the whole team while thanking them for their generosity.

It really hammered that lesson home and the victims did honor the cake-mails. Only downside was, that this led to people to tryimg to bait each other into leaving their PCs unlocked and creative countermeasures, such as delaying mails containing the word 'cake'.

I created a little script that ran on startup that would wait a random amount of time between 5 and 15 mins and would just hit the left key once. I dropped it on a dev's computer when he left it unlocked and forgot about it. After weeks of torment, it activated while he had a YouTube video so he figured out it wasn't his fault. He was convinced it was the keyboard and started harassing IT so I had to come clean.

Jokes on me though, every time there was any quirk on his computer, server, or with his code he blamed me and didn't believe me.

Or have some fun with https://whitescreen.tv/fake-blue-screen/

It is a good practice to start what we call "Hasslehoffing"

It is where you change the background to a picture of David Hasslehoff every time someone leaves their PC unlocked for a long enough time to change the background. The more it happens, the sexier he gets.

I urge other colleagues to do the same. The only defense there is against that is to lock your PC every time you leave your desk. It really works.

open their Teams and send "I'm bringing cake next week" in the group chat on their behalf.