Yesterday, American Airlines started charging customers $15 for the first checked bag, a controversial but necessary move given rising oil prices (American, like many other airline carriers, also charges $25 for the second checked bag). Though full fare, gold/platinum frequent fliers, first and business class customers, are exempt from the fee, American expects 25% of its customers to be affected by the charge. And those fliers were not happy. One traveler at LaGuardia told the......