Wow! I love this subject matter. Before my trucking days, I had this one apartment for about six years and all sorts of bad neighbors came and went. It was one of my pet peeves to see garbage bags left in front of doors. My tactic was to slip by late at night and quietly move said garbage bag directly in front and up against the offending neighbor's door. It seemed that most folks don't like having to move smelly garbage bags first when exiting their apartments. There weren't too many repeat incidents after my doing that.