[MRM]

There are possible licensing issues with doing business on the street. You might need a permit to have a sidewalk kiosk as you describe. Also, most cops don't know the law. They just order people around and if they don't do as they're told, they arrest them for disorderly conduct or disobeying a lawful order. But since cops don't really know what their authority is, I would contact a lawyer who is experienced in representing local businesses or protesters, and who can advise you as to the proper permits, restrictions, etc. Then get that lawyer to write you a letter you can show the cop stating that you are legally protected, and why. The letter should advise the cop harassing you to call the city attorney or DA on duty for a legal opinion before hauling you off, and advising that since he has now been put on notice that arresting you would violate your civil rights, any violation of your rights would be considered deliberate, exposing the city and cop to corporate and personal liability under 42 USC 1983, et seq.