Past research on location-sharing technologies and social media has uncovered many types of privacy concerns such as informational privacy, impression management and interactional privacy. We interviewed 21 users and nonusers of location-sharing technology and found that many of these privacy concerns are actually just symptoms of a higher-level motivation: the desire to preserve one’s existing offline relationship boundaries. We confirmed and generalized this finding through a nation-wide survey (N=1532) and path analysis. These results imply that designers of location-sharing systems should focus on preserving users’ relationship boundaries to address this cause of privacy concerns.