Tracking information of individuals is a useful input to many Ubiquitous Computing (UbiComp) applications. Consider the example of a smart emergency management application: once mobile first responders are continuously tracked, a precise and safe coordination of rescue missions is possible, and also mission logs can be created for audit purposes. However, continuously tracking users and storing the data for later use is often in conflict with individual privacy preferences. This may ultimately lead to the non-acceptance and rejection of these new technologies by their users. In order to reconcile privacy and accountability requirements in location tracking systems, we introduce and evaluate the approach of using auditing mechanisms on two levels. We illustrate that, by employing carefully designed cryptographic mechanisms for selective pseudonym linkability based on efficient techniques of secure multiparty computation, it is possible to balance the conflicting interests to a certain extent. Our work, motivated by and applied to smart emergency management systems, is a step towards the realization of multilaterally secure and thus multilaterally acceptable UbiComp systems supporting collaborative work.