The proliferation of sensors, social networks, and massive data repositories presents an unprecedented opportunity to study human behavior. But this opportunity poses new challenges to the protection of individuals and groups by respecting privacy and autonomy, ensuring data security, and considering unforeseen consequences. Organizations have been left with research ethics frameworks and legacy consent processes that are poorly suited for modern data analyses and extended timescales. By marrying legal and policy analysis of informed consent with careful explication of respect itself, we plan to develop a penetrating discussion of 1) the ideal of respect for persons and 2) how informed consent has, at various point in its development, sought to operationalize this ideal in various contexts. Foregrounding the connection between respect and informed consentand critically interrogating bothis, we argue, an integral step towards the development of a 21st century research ethic and actionable policy recommendations.