AT&T Mobility v. Concepcion, 563 U.S. 333 (2011), is a legal dispute that was decided by the United States Supreme Court. On April 27, 2011, the Court ruled, by a 5–4 margin, that the Federal Arbitration Act of 1925 preempts state laws that prohibit contracts from disallowing class-wide arbitration, such as the law previously upheld by the California Supreme Court in the case of Discover Bank v. Superior Court. As a result, businesses that include arbitration agreements with class action waivers can require consumers to bring claims only in individual arbitrations, rather than in court as part of a class action. The decision was described by Jean Sternlight as a "tsunami that is wiping out existing and potential consumer and employment class actions" and by law professor Myriam Gilles as "