The following passive-aggressive note expresses more disgust and derision than most of the entries on this list. A colleague snatched a slice of pizza but didn’t finish the entire thing. Instead, they baited the owner by taking a couple of bites and discarding the sad remnants in the box.
This is extremely depressing because nobody would want to touch it after someone else’s mouth was on it. Either they lacked self-awareness or they didn’t care about upsetting their colleague. We see the response where the victim thanked the thief for considering eating the entire thing next time (via Bored Panda).