These protesters frequently block the sidewalk and disturb the peace. Can they be moved further away?

Issue is corrected for the moment but I have no doubt these signs will be back.

These signs might be illegal, I don't know. However the protesters themselves have a legal right to be there, are peaceful and do not disturb the peace, and leave room on the sidewalk for people to pass and move further out of the way when people do pass. Even if one disagrees with them, they are peaceful. The sign may be a different issue if it is left there permanently and the property owner does not allow it. I believe protesters are allowed to display signs while they are present.