On October 7, 2009, the Department of Homeland Security officially rescinded its August 2007 rule establishing "safe-harbor procedures" for employers who receive Social Security no-match letters. These procedures never went into effect because a federal court in California issued a preliminary injunction against the rule after the AFL-CIO and other organizations filed suit. The rescission reinstates the former rule on what constitutes "constructive knowledge" on the part of an employer that an employee is working without authorization. The final rule, as published in the Federal Register, may be read here.