The proliferation of Internet of Things (IoT) devices for consumer "smart" homes raises concerns about user privacy. We present a survey method based on the Contextual Integrity (CI) privacy framework that can quickly and efficiently discover privacy norms at scale. We apply the method to discover privacy norms in the smart home context, surveying 1,731 American adults on Amazon Mechanical Turk. For $2,800 and in less than six hours, we measured the acceptability of 3,840 information flows representing a combinatorial space of smart home devices sending consumer information to first and third-party recipients under various conditions. Our results provide actionable recommendations for IoT device manufacturers, including design best practices and instructions for adopting our method for further research.CCS Concepts: • Security and privacy → Human and societal aspects of security and privacy; Privacy protections;• Human-centered computing → Empirical studies in ubiquitous and mobile computing;In this paper, we present a general, scalable survey method for discovering consumer privacy norms based on the Contextual Integrity (CI) privacy framework [44] (Section 3). CI is a well-established theory that defines privacy norms as the generally accepted appropriateness of specific information exchanges, or "information flows," in specific contexts. Information flows and associated contexts can be described using five parameters: sender, recipient, subject, attribute, and transmission principle. This precise formulation makes it possible to thoroughly investigate the combinatorial space of contextual information flows and associated privacy norms with an automated, large-scale survey on a crowdsourcing platform. Our use of CI also ensures that the method is repeatable, both for the same types of devices over time, as well as for entirely new classes of devices.The method we develop is effective for discovering privacy norms in general. In this paper, we focus on applying the method to discover smart home privacy norms. We conducted a survey with a population of 1,731 adults from the United States on the Amazon Mechanical Turk (MTurk) platform. The survey cost $2,800 and allowed us to query the acceptability of 3,840 information flows involving smart home devices in less than six hours and identify associated privacy norms (Section 4). Our results provide insightful observations and actionable recommendations for IoT device manufacturers, regulators, and consumer advocates (Section 5).Device manufacturers can use our survey method to perform their own research on how consumers might view the use of data that their products collect. We designed the method to make it easy to customize with new information flows and contexts, allowing manufacturers to discover privacy norms relevant to specific products, including ones we have not studied in this paper. The results will indicate whether existing or proposed devices may violate established privacy norms, providing an opportunity to preempt negative user feedback, public relati...