In an important decision that reinvigorates the protections of Rule 23 of the Federal Rules of Civil Procedure, the U.S. Supreme Court blocked an at-tempt to certify a class of approximately 1.5 million employees of Wal-Mart Stores, Inc. alleging gender discrimination. The Court’s decision puts an end to what it referred to as “one of the most expansive class actions ever” and requires heightened scrutiny of class actions in all areas of the law, including mass torts and antitrust.