The AT&T case was not specifically about class until it hit the SCOTUS. The case was originally found for AT&T, with the court finding the clause was fine. The California Federal Circuit court reversed that decision, because it felt the clause was 'unconscionable' because it also signed away the right to sue as a class. The SCOTUS rejected that interpretation, upholding not only clauses that deny the right to sue as a class, but the arbitration clause itself.