Empirical Models of Privacy in Location Sharing

The rapid adoption of location tracking and mobile social
networking technologies raises significant privacy challenges.
Today our understanding of people's location sharing privacy
preferences remains very limited, including how these
preferences are impacted by the type of location tracking device
or the nature of the locations visited. To address this
gap, we deployed Locaccino, a mobile location sharing system,
in a four week long field study, where we examined the
behavior of study participants (n=28) who shared their location
with their acquaintances (n = 373.) Our results show
that users appear more comfortable sharing their presence at
locations visited by a large and diverse set of people. Our
study also indicates that people who visit a wider number
of places tend to also be the subject of a greater number of
requests for their locations. Over time these same people
tend to also evolve more sophisticated privacy preferences,
reflected by an increase in time- and location-based restrictions.
We conclude by discussing the implications our findings.