• Participatory sensing is a specialized form of crowdsourcing for mobile devices in which the users act as sensors to report on local environmental conditions. • This poster describes the process of prototyping a mobile phone crowdsourcing app for monitoring parking availability on a large university campus. • We present a case study of how an agent-based urban model can be used to perform a sensitivity analysis of the comparative susceptibility of different data fusion paradigms to potentially troublesome user behaviors: 1. Poor user enrollment, 2. Infrequent usage, 3. A preponderance of untrustworthy users.