When I got my dog a few years ago, she would sometimes bark when I wasn't home. This is all pretty normal for a new puppy. My neighbor at the time disagreed. After about a week or so I came home to find a note taped to my door saying my "dog won't shut up" and that I that suck, and my dog sucked, and that we should both die. So you know, real neighborly advice.
Another time, I ran into my apartment to grab something and then immediately left. As I was locking the door to my apartment, my neighbor stormed out into the hallway to tell me that I was being too loud and need to stop opening and closing the door so much. I guess using a door twice was too much for him.
I did what anyone would do in this situation. I waited for him to move and fortunately the new guy loved my dog. Just goes to show you that everything turns out okay if you just are patient and don't escalate a situation. If you're feeling burned by your own neighbor, I promise, you will feel at least a little better after reading these horror stories, below: