My Privacy Policy: Exploring End-user Specification of Free-form Location Access Rules

The increasing inclusion of location and other contextual information in social media applications requires users to be more aware of what their location disclosures reveal. As such, it is important to consider whether existing access-control mechanisms for managing location sharing meet the needs of today’s users. We report on a questionnaire (N = 103) in which respondents were asked to specify location access control rules using free-form everyday language. Respondents also rated and ranked the importance of a variety of contextual factors that could influence their decisions for allowing or disallowing access to their location. Our findings validate some prior results (e.g., the recipient was the most highly rated and ranked factor and appeared most often in free-form rules) while challenging others (e.g., time-based constraints were deemed relatively less important, despite being features of multiple location-sharing services). We also identified several themes in the free-form rules (e.g., special rules for emergency situations). Our findings can inform the design of tools to empower end users to articulate and capture their access-control preferences more effectively.