A galaxy of user-generated data points is providing a near-unimaginable quantity of data that can improve disaster preparedness and response. But there are some problems that must be overcome, warn Ian Portelli, Ramin Bajoghli, Megan Mantaro and Amanda Horowitz - Written by Ian Portelli, Ramin Bajoghli, Megan E Mantaro and Amanda Horowitz. (Volume 10, Issue 3)