The things we call “phones” are advanced sensing platforms with location awareness that we carry around with us in large numbers. 

This – and other massive data, such as tweets or Google searches – can, in aggregate, reveal surprising things about the world, without building any new infrastructure, deploying any additional devices, or asking people to provide any extra data. We can just mine the data that people are already creating by going about their daily lives. 

There are obvious privacy and data ownership issues from this. 

(28 minutes.)

https://www.youtube.com/watch?v=N3tV_YAB_iU&feature=share