In most circumstances, officers will not immediately bull rush you for filming them. But if they aren’t properly trained, they might feel like their authority is being challenged. And all too often police are simply ignorant of the law. Part of your task will be to convince them that you’re not a threat while also standing your ground. Instead, say something like “Officer, I’m not interfering. I’m asserting my First Amendment rights. You’re being documented and recorded offsite.” In the United States there’s no law requiring you to carry a government ID. But in 24 states police may require you to identify yourself if they have reasonable suspicion that you’re involved in criminal activity. But how can you tell if an officer asking for ID has reasonable suspicion? Police need reasonable suspicion to detain you, so one way to tell if they have reasonable suspicion is to determine if you're free to go. You can do this by saying "Officer, are you detaining me, or am I free to go?"