What do you call someone who is obsessed with calling the cops?

Someone who is obsessed with calling the cops may be referred to as a "police caller" or even a "911 caller." In some contexts, they might be labeled as a "busybody" or "nosy neighbor," especially if their calls are about minor issues. If the behavior is excessive or unwarranted, it may also be described as "overly vigilant" or "overzealous."