Social media are extraordinary communication and preservation tools brimming with fonts of incriminating, exculpating, and impeaching evidence. Legal professionals have already added online profiles, instant messaging, and videos to the list of information sources about their clients, their opponents, and their potential witnesses. Still, the bulk of legal authority and ethical guidance is rooted in precedent based on antecedent technologies, which has little resemblance to the emerging social centers of cyberspace. No guidelines for criminal defense discovery or investigation within networked social spaces can be found in existing statutes and ethics codes. One ethics committee has taken the lead on this issue in an opinion curtailing the limits of surreptitious witness investigation through Facebook. Defense counsel‟s duty to zealously and effectively represent their clients, the practical desire to avoid being sued for malpractice, and the promotion of the fair administration of justice all require a clear demarcation of the ethical and constitutional boundaries for accessing and using data from social networking sites. This Article will examine the dual nature of social media as a communication conduit and information warehouse, the meaning of privacy in this environment, and the ethical and legal dilemmas inherent in prosecuting and defending cases with this new breed of evidence. * Director of Legal Information Services, New York State Defenders Association. J.D., Temple University School of Law, 1984; M.L.S. St. John‟s University, 1994; B.A., summa cum laude, St. John‟s University, 1981.