Did Anybody See That? Smartphone Tracking for Historical Data Retrieval
Smartphones have revolutionized the way in which sensing has been performed traditionally. The people-centric nature of Smartphone-based sensing enables them to be a part of participatory or opportunistic sensing, where data is collected on a set of designated Smartphones and delivered to a server. In this paper, the authors identify the existence of another type of behavior, where the data is not delivered but archived locally on the phones for later retrieval. This type of behavior is common when the phone users capture some data (e.g. a video clip) out of their own interest.