Mobile sensing combines the ubiquity of mobile phones with sensing capabilities typical of Wireless Sensor Networks (WSNs). Since the mobile phones are extremely mobile, they leverage the ambulation of their carriers. Moreover, in traditional WSNs, the network operator is assumed to own and query all sensors, while this assumption does not apply to most mobile sensing scenarios. Indeed, mobile devices are tasked to participate into gathering and sharing local knowledge. The strong focus on the collection of detailed sensor data may however compromise user privacy in various regards, e.g., by tracking a user's current location.