(Do Not) Track Me Sometimes: Users' Contextual Preferences for Web Tracking

Online trackers compile profiles on users for targeting ads, customizing websites, and selling users’ information. In this paper, we report on the first detailed study of the perceived benefits and risks of tracking—and the reasons behind them—conducted in the context of users’ own browsing histories. Prior work has studied this in the abstract; in contrast, we collected browsing histories from and interviewed 35 people about the perceived benefits and risks of online tracking in the context of their own browsing behavior. We find that many users want more control over tracking and think that controlled tracking has benefits, but are unwilling to put in the effort to control tracking or distrust current tools. We confirm previous findings that users’ general attitudes about tracking are often at odds with their comfort in specific situations. We also identify specific situational factors that contribute to users’ preferences about online tracking and explore how and why. Finally, we examine a sample of popular tools for controlling tracking and show that they only partially address the situational factors driving users’ preferences. We suggest opportunities to improve such tools, and explore the use of a classifier to automatically determine whether a user would be comfortable with tracking on a particular page visit; our results suggest this is a promising direction for future work.