Last year in Butler v. Sears, Roebuck & Co., the U.S. Court of Appeals for the Seventh Circuit overturned a district court's denial of certification for a class of plaintiffs who alleged injury resulting from a mold-causing defect in Whirlpool-manufactured washing machines. On appeal, Sears argued that plaintiffs failed to satisfy the requirement of predominance in class action litigation, but to no avail. Announcing that "Predominance is a question of efficiency," Judge Richard Posner (writing for the court) concluded that the class should be certified for the sake of efficiency—even though not every plaintiff actually encountered the alleged mold problem, and even though the suit implicated some twenty-seven different washer models. Sears went on to petition the Supreme Court for certiorari.