One of the Internets defining characteristics is the freedom it gives users to make anonymous remarks. As many employers have discovered, however, employees can abuse that freedom by posting information online That defames management or divulges proprietary information. Employers faced with such online misconduct must try to unmask unknown "posters" who have valid arguments about their First Amendment right to speak. without attribution and remain anonymous. This article describes bow Internet message boards work, summarizes the competing interests of employers and employees with respect to the messages posted there, describes what employers may do to respond short of litigation, and outlines The numerous issues raised in suing an unknown employee. It also provides some suggestions for how employers can be better prepared to identify employees who have posted such messages.