Will the next great medical insight come from a clinical trial, a laboratory study — or a database search? Today, health systems and insurers have access to a mountain of data about millions of Americans: what medications they take, their health history, even, in some cases, their genetics—plus an emerging body of mobile health data. Using “big data” techniques, doctors and researchers are already mining this data to deliver better care and to gain insights into the kind of hyper-specific questions that clinical trials and observational studies struggle to answer. The approach promises major, rapid-fire, highly-personalized discoveries. At the same time, with the specter of cyberattacks and hacks looming, the need for rugged privacy protection has never been greater. In this Forum, experts in healthcare data and privacy will discuss the potential for future discovery, practical steps to enable progress, and how information can be kept secure. Part of the The Dr. Lawrence H. and Roberta Cohn Forums, this event was presented jointly with HuffPost on Tuesday, December 5, 2017. Watch the entire series at ForumHSPH.org.