This article reports on the planning, development, and implementation of a large national Internet-based panel study of how Americans are coping with the terrorist attacks of September 11, 2001. The study was designed to determine predictors and correlates of risk and resilience, both cross-sectionally and longitudinally. In order to acquire timely and meaningful data, we developed/adapted an extensive set of measures, obtained human subjects approval, and posted a research Web site just 17 days after the attacks. This article describes the major hurdles we confronted and the guidelines we recommend regarding these topics, including the methodological trade-offs inherent in Internet-based research, information technology requirements and tribulations, human subjects issues, selection of measures and securing permission for their use, and the challenges of participant recruitment. We also discuss issues that we did not anticipate, including the survey intervention. We focus not on findings, but on the concrete procedural, administrative, technical, and scientific challenges we encountered and the solutions we devised under considerable time and resource pressures.