I'm reminded of how the Chaos Congress organizers persuaded the Leipzig public transportation agency to run around-the-clock service to the congress: He showed

I'm reminded of how the Chaos Congress organizers persuaded the Leipzig public transportation agency to run around-the-clock service to the congress: He showed them the curve of devices logged into wifi for the last year. It has a steep decline somewhere at night, which is when people leave. With all the location data Google & Co have they should try their hand at making plans for public transport systems (if they haven't already).