Quantified self, from Fitbit to Sleep Cycle, is a proven market. It has happened. The data generated can provide huge insight at scale. This was illustrated when Jawbone issued stats on who woke up during the South Napa earthquake in 2014. We could design better transport, better healthcare, and better cities if we could design better sharing of this valuable data.People happily post their lives to Facebook, their movement to Moves, or wear a wristband to measure (and to share) their activity, but will freak out if we count them entering a park. This 10-minute talk is about public participation, privacy, and an urban alternative to the "rewards" we get at the personal scale.