My sister has always had a petty streak, but my favorite example is from when she lived with her ex-boyfriend.

Every time they got into an argument, she would move all of the furniture in their apartment by one inch in the same direction - literally every piece of furniture and decor. Her boyfriend would feel like something was off, but nothing was immediately obvious because she didn't move just one thing - she moved everything.

The space between the objects was the same, so he would be confused as to why he was suddenly tripping over things, running into furniture, catching his clothes on things, etc.

The worst part was that she would leave it until he got used to it, and the next time he made her mad she moved it all back an inch in the other direction and the cycle continued.

I honestly don't think he ever figured it out, and I probably would have felt bad for him if she hadn't caught him cheating on her - which led to her freezing his car keys, storage unit keys, etc. in separate blocks of ice, removing absolutely everything she had ever purchased from the apartment (including all of the light bulbs, towels, toilet paper, silverware, etc.) and sending the screenshots of him cheating on her to his mom. She had also paid for his contact prescription, so she took those too - leaving him only the pair of glasses he had when they met.

She also put shrimp in all of the curtain rods, and according to their mutual friends he never figured out the source of the smell and eventually moved apartments to get away from it.