There's a story that I've heard a number of times about an old shell-backed Yankee surf fisherman who got tired of having his fishing line cut by boaters trolling by his favorite rocky outcrop and molded a six or eight ounce lead Diamond Jig with razor blades embedded all along the sides. He would wait until the boat just passed his position and cast the contraption across the trolling lines at the back of the boat. Rumor had it that he managed to cut every line most of time. He became such a fixture that his friends would identify themselves and ask to take a couple of trolling passes by the defended rock. Others stayed away when he was fishing. Some boaters are enough to make you want to bring back the cannon.