I guess you could call this harmless as no one got hurt, thankfully. I was in my late teens and took a paper grocery bag full of fireworks, lit it on fire and threw it in the door of the police station in our little town. It was in January and there had been a freezing rain that evening. As we drove away looking back the officers came running out, falling on the ice. It was about 10:30 PM at shift change so most of them were in there. We got caught.