Missing people, animals or objects is a common problem. Many tracking systems are based on technologies that are expensive, demands large devices to be carried, or demands often battery charging. Approaches using cameras or RFID systems usually have the problem of requiring covering the search area with sensors. This work takes advantage of the Internet of Things proposing a system for finding targets using the Swarm, which enables to opportunistically gather heterogeneous resources of third parties. A use case was deployed and evaluated.