I printed out the infamous quote "Go away, or I will replace you with a small shell script." It was primarily meant for one specific employee known to have the gift of gab. Seeing how my job was to automate the most mundane/error prone tasks, it seemed to be pretty effective. I heard murmurings about how some thought it was rather rude, but I never had to speak to HR about it.

Make them fear the dark wizard’s powers.