Four trademark infringement scenarios. Spot the real one:Late one winter night, an old pickup gives out and the driver is forced to pull off onto the shoulder of a desolate country road. Fortunately, he belongs to the Automobile Association of America. Pulling out his cellphone, the cold, tired driver accidentally dials the “other” AAA, the American Arbitration Association. He later reports his confusion to the driving group, leading one AAA to file suit against the other.So excited are a newly engaged couple …