At&t Mobility LLC v. Concepcion

Summary

The Court reversed the Ninth Circuit, holding the Federal Arbitration Act preempts California's Discover Bank rule that deemed class-action waivers unconscionable. The majority found class arbitration interferes with the informality and efficiency that are fundamental to arbitration agreements. Justice Thomas concurred, offering a narrower textual rationale, and Justice Breyer dissented, arguing the rule was consistent with the FAA’s purposes.