In my experience, you are not in too much danger from the normal uniformed police if you handle them courteously. By explaining calmly that you will try to disturb nobody and that you are earning your living, you can often negotiate a sensible compromise. Of course, usually, if some local windbag orders the police to remove you - or even charge you, they have to do it. In practice, the police will come if they have to, but they are unlikely to come rushing out with sirens and flashing blue lights. They feel more comfortable nicking real criminals.