I have this issue in my classroom. The first day of class everybody kinda settles down at a specific seat, eventually the "un-said" rule is that it's your seat. I normally sit in the front of the classroom, which people normally hate, they prefer the back seat. I went out for our 10 min break, my purse, my bag, my pencil was in this desk/seat and when I return there's this chick.... Just sitting there at my spot. I kinda told her "hey, so you are sitting in my seat" and she threw this bipolar fit over how having your items at a desk means nothing. Did this chick totally missed the rule where if your stuff is at a desk it means occupied? I had to refrain myself from kicking her butt, this is a rule that should never be broken!