When I was in the 8th grade I lived in a three story house. We were on the top floor and our porch was directly over the landlord's porch. We hated them and always threw things over to their porch.
One hot summer day my best friend was over and we were really bored, so we decided to play truth or dare. My sister dared my best friend to pee in a bag and throw it over to the landlord's porch.
We didn't expect her to really do it, but she went into the bathroom and not only did she pee in the bag, but she let out some #2. We were pretty embarrassed but decided to throw it down on their porch anyway.
They didn't realize it was there for a month! We expected to be in trouble, but it turned out that they blamed their grandson. We moved the next mouth and I haven't spoken to them since.