@WBC posted:An update.
BNSF did sue Northern Pacific Airlines for trademark infringement.
Unfortunately for BNSF, their trademark involved rail transportation, not "transportation" in general. Unless the planes run on rails, their legal challenge is likely to be unsuccessful. Often times large corporations will file suits like these in an attempt to bludgeon their opponent into submission. Many smaller companies simply can't afford the legal fees and costs to challenge and win.
