ALT Exploring User Motivations Behind iOS App Tracking Transparency Decisions Apple’s App Tracking Transparency framework allows users to decide whether they want to allow their activity to be tracked for advertising purposes. In this work we examine the tracking decisions made by 312 participants and their associations with privacy concern and personality factors, and conduct a thematic analysis on participants’ reasons for choosing to accept or reject tracking requests. Despite 51% of participants reporting that they had rejected tracking for privacy reasons, higher privacy concern scores did not correlate with a lower rate of tracking acceptance. Additionally, 43% of participants held incorrect beliefs about what tracking does, including nearly a quarter who mistakenly believed that accepting a tracking request would share their location with the requesting app. We suggest explanations for these misconceptions and provide recommendations that may improve usability of both App Tracki...