A Strange Burglar
When I was in university, living in residence, I was doing laundry on a Friday night, so no one else was around. I put my stuff in the washer and then realized I had forgotten my headphones. I went back up to my room to grab them, so I was gone for maybe five minutes. In that time, someone went through the washer and took only my underwear.
A couple of weeks later, someone started leaving my underwear on the doorknob of my room, pair by pair. It stopped after about two months, but whoever it was never got caught leaving the underwear. They must have known me and known my schedule perfectly.
Story credit: Reddit / ndanielmd