Oh my gosh, I feel the same way when people touch my things. I hate it. I remember having intense tantrums when I was a kid and my mom would clean my room. I felt so violated and disorganized afterwards. I had everything the way I wanted it, it made sense to me even though maybe it didn't look pretty. I always thought, I don't go into your room and clean it for you so why are you going into mine? When I would talk to her about it she would deny that she cleaned it. What??? How else did it get that way cause I certainly didn't do it!!
People at work have learned to leave my desk alone too. I would come in sometimes and have papers all over it that they dropped off or stuff would be moved. Once a co-worker used my desk lamp and didn't put it back, I flipped out. I felt really bad afterwards but it was really personal and affronting to have my space interfered with.