Consumers who purchased Xbox 360s sued Microsoft both individually and as a class. The district court struck the class allegations, refusing to certify the class. The Ninth Circuit refused to hear the appeal of that ruling under Fed. R. Civ. P. 23(f), which allows such interlocutory appeals only by permission of the court of appeals. Instead of pursuing their individual claims, the consumers stipulated to a voluntary dismissal of their claims with prejudice, and then appealed the dismissal to challenge the class certification ruling. The Ninth Circuit held that it could entertain the appeal. A five-member majority opinion authored by Justice Ginsburg reversed, holding that the consumers’ approach was an improper end-around to Rule 23(f)’s narrow allowance for such interlocutory appeals. The majority noted that such voluntary dismissal appeals only invited more protracted litigation than so-called “death-knell theory,” which permitted such interlocutory appeals where the denial of class certification was the death-knell to the case. The Court rejected that theory in 1978, and saw no need now to further extend the ability of the appellate courts to hear such appeals. Justice Thomas, joined by Chief Justice Roberts and Justice Alito, agreed that the appeals were improper, but on the basis that once the consumers agreed to a voluntary dismissal, there was no case or controversy to appeal under Article III of the Constitution. A link to the opinion in Microsoft Corp. v. Baker is here.