The Internet has become a critical medium for clinicians, public health practitioners, and laypeople seeking health information. Data about diseases and outbreaks are disseminated not only through online announcements by government agencies but also through informal channels, ranging from press reports to blogs to chat rooms to analyses of Web searches (see Digital Resources for Disease Detection). Collectively, these sources provide a view of global health that is fundamentally different from that yielded by the disease reporting of the traditional public health infrastructure.1 Digital Resources for Disease Detection.Sample Web-based data sourcesProMED-mail, www.promedmail.orgGlobal Public Health Intelligence Network (GPHIN), . . .