CDC develops and delivers health messages for a variety of audiences, including the public, health care professionals, public health researchers and practitioners, and policy makers. News media outlets--because of their broad reach and potential to influence knowledge, attitudes, and behaviors--are major channels for disseminating messages to these audiences. CDC has routinely monitored news outlets to identify message/information gaps and opportunities. The 9/11 terrorist attacks and the anthrax incidents that followed required CDC to transform its media monitoring system into a broader communication monitoring system, with both listening and telling functions, to support CDC's public health emergency response.