International Journal of Human-Computer Interaction, 2026 (SCI-Expanded, SSCI, Scopus)
Online shared content, such as group pictures, often belongs to multiple users having different privacy preferences. Recent technical approaches advocate group-decision mechanisms, including auctions, to decide how best to resolve these differences. However, it is unclear if users would participate in such mechanisms or whether they would act altruistically. Understanding these dynamics is crucial for privacy-respecting collaborative systems. Accordingly, we present RESOLVE, a privacy auction game to understand the sharing behavior in groups. Through an experiment with this game, participants expressed individual preferences for their own photos and later revisited them when placed in a group context with and without knowing others’ preferences. Our results of users’ playing the game show that i) the users’ understanding of individual vs. group privacy differs significantly; ii) often users fight for their preferences even at the cost of others’ privacy; and iii) at times users collaborate to fight for the privacy of others.