(((They weren’t blocking anything. They were at least 15 feet from the entrance.)))
They were holding the banner parallel to the street blocking anybody from pulling up to the front and walking straight in. If my customer has to walk around you to get in your blocking the entrance.
If your customer has to walk around me to get to you, and I’m on a public sidewalk, that may inconvenience your customer, but doesn’t give you any right to forcibly move me or take my property