If you are in the same place for a long period of time, especially if you return several days in a row, you may be asked for a permit. In this case it just important to retain the ability to go mobile at a moment's notice. You will probably just be asked to leave the first couple times after you have over stayed, but after that they may attempt to damage or confiscate you equipment. The second there is unusual attention on your crew you need to communicate with everyone about moving quickly. Create an escape plan well ahead of time if you are going to have to “shoot and run.” If it does look like your equipment is going to get confiscated, or even your footage, make sure to keep a blank dummy tape on board that you can switch with the one in the camera. In this situation you may want to keep the camera running during the whole episode for footage or documentation for legal liability purposes. You may want to put a tiny strip of electrical tape of the red “record” light that is in the front of the camera. This way you will be able to say that you are not recording even when you decide to keep it rolling.