This antitrust case was brought as a class action challenging bag fees charged by Delta Airlines and AirTran Airlines. The district court granted class certification, and the defendants appealed. Public Citizen, joined by the National Consumer Law Center, filed an amicus brief in support of the plaintiffs. The brief explained that, contrary to the defendants’ argument, “administrative feasibility” is a threshold prerequisite to class certification. The court, however, decided the case on other grounds, without addressing class certification.