*Call for Papers: "Social Media Data for Public Health and Policy" IJERPH* This special issue seeks original submissions that harness social media to examine: (1) health or health policy-related discussions, attitudes, and behaviors, (2) online marketing and promotional practices of companies and services that may influence health behaviors, (3) interventions that use social media as tools in intervention delivery, (4) applications of data science or computational social science methods in the health domain, (5) critical analysis of the role of social media in public health, (6) theory-driven approaches to social media-based inquiries, and/or (7) relevant systematic reviews Deadline: June 1, 2020. More information: https://www.mdpi.com/journal/ijerph/special_issues/mr_socmedia