Karina Elzer, Eric Jedermann, Stefanie Roos, Jens Schmitt

• This poster was first presented on EuroS&P 2025 in Venice. In many places, a surge of micro-mobility sharing systems, as for instance e-scooters, can be observed. Shared micro-mobility is a cost-efficient and flexible alternative to owning vehicles and, furthermore, leads to reduced traffic and air pollution. However, sharing information about vehicles impacts the privacy of the individuals using such vehicles as changes in vehicle state are linked to an individual’s mobility pattern. Malicious exploitation of knowledge on mobility patterns of individuals may assist in criminal activities such as stalking or burglary. Thus, it is very important that micro-mobility sharing platforms do not leak sensitive data about the mobility patterns of their users, resulting in a tradeoff between sharing and privacy. To characterize the privacy leakage in one specific instance of shared micro-mobility, we conducted a large-scale, long-term data collection from scooters run by the e-scooter company Tier in the European university town Kaiserslautern. Indeed, the data reveals several privacy issues: For instance, we were able to reconstruct work and school schedules of various individuals. Furthermore, we could infer interests and hobbies by visits to, e.g., sports facilities. Our initial discovery of such leakages was aided by the fact that the specific e-scooter company does not comply with existing privacy standards, in particular the use of dynamic IDs. Yet, an a-posteriori analysis of our data shows that even with dynamic IDs, we are able to re-construct 80% of the trips, which still constitutes a substantial privacy leakage.