I had a job creating computer graphics, printing out files for clients, writing content. Immediate manager was a glory thief who took credit for a lot of the graphic work I turned out. I didn't say anything, but after the first few times of him getting complimented for MY work, I got crafty.
I used Photoshop a lot, so I made two blacks in the palette and buried my signature. Boss came around after one of those review meetings where manager was again showered in praise, asked if everything was okay and I said no. No, it's not okay when Jim takes all credit for my work.
Boss says, “He claims to have created this piece.” So I opened the file, changed one of the blacks to bright red and, lo! My name in lights!
They found an excuse to let me go days later, but the joke's on Jim cuz he couldn't graphic his way out of a paper bag. Found out later he got fired.
Went by that place a few months ago. It's gone. Serves 'em right for making stupid decisions.