A number of mobile applications have
emerged that allow users to locate one another.
However, people have expressed concerns about the
privacy implications associated with this class of
software, suggesting that broad adoption may only
happen to the extent that these concerns are adequately
addressed. In this article, we report on our work on
PEOPLEFINDER, an application that enables cell phone
and laptop users to selectively share their locations
with others (e.g. friends, family, and colleagues). The
objective of our work has been to better understand
people’s attitudes and behaviors towards privacy as
they interact with such an application, and to explore
technologies that empower users to more effectively
and efficiently specify their privacy preferences (or
“policies”). These technologies include user interfaces
for specifying rules and auditing disclosures, as well as
machine learning techniques to see if the system can
help people manage their policies better. We present
evaluations of these technologies in the context of one
laboratory study and three field studies