David Clark is a Senior Research Scientist at the MIT Computer Science and Artificial Intelligence Laboratory. Since the mid-70s, he has been leading the development of the Internet; from 1981-1989 he acted as Chief Protocol Architect in this development, and chaired the Internet Activities Board. His design research looks at re-definition of the architectural underpinnings of the Internet, and the relation of technology and architecture to economic, societal and policy considerations. He supported the U.S. National Science Foundation Future Internet Architecture program. His current priorities include Internet security, the challenges of large-scale collection and curation of data about the Internet, and mitigating the abusive uses of Internet applications. He is past chairman of the Computer Science and Telecommunications Board of the National Academies, and has contributed to a number of studies on the societal and policy impact of computer communications. He is a Fellow of the National Academy of Engineering and the American Academy of Arts and Sciences.