Abstract: Determining which photos are sensitive is difficult. Although emerging computer vision systems can label content items, previous attempts to distinguish private or sensitive content fall short. There is no human-centered taxonomy that describes what content is sensitive or how sharing preferences for content differs across recipients. To fill this gap, we introduce a new sensitive content elicitation method which surmounts limitations of previous approaches, and, using this new method, collected sensitive content from 116 participants. We also recorded participants’ sharing preferences with 20 recipient groups. Next, we conducted a card sort to surface user-defined categories of sensitive content. Using data from these studies, we generated a taxonomy that identifies 28 categories of sensitive content. We also establish how sharing preferences for content differs across groups of recipients. This taxonomy can serve as a framework for understanding photo privacy, which can, in turn, inform new photo privacy protection mechanisms.