The potential loss of privacy due to the use of locationbased applications may be one of the greatest obstacles to their wider acceptance. Nevertheless, most research about privacy management to-date has not taken into consideration the complexity in the utilization of collaborative applications that may require users' location sharing among participants. In this article, we propose a privacy service that helps users to maintain their privacy policy in a flexible and incremental way. We also carried out a qualitative evaluation study whose results illustrate several challenges that should be handled in the design of such a service.