They place phone calls, surf the Internet, and there are close to four billion of them in the world. Their built-in microphones, cameras, and location awareness can collect images, sound, and GPS data. Beyond chatting and texting, these features could make phones ubiquitous, familiar tools for quantifying personal patterns and habits. They could also be platforms for thousands to document a neighborhood, gather evidence to make a case, or study mobility and health. This data could help you understand your daily carbon footprint, exposure to air pollution, exercise habits, and frequency of interactions with family and friends.
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