By clicking "Like" and commenting on Facebook posts, users signal the social network's algorithm that they care about something. That in turn helps influence what they see later. Algorithms like that happen all over the web — and the programs can reflect human biases.
Traffic stands still in Nairobi. People in Kenya's capital don't like getting into cabs driven by strangers. They prefer to call drivers they know or who their friends recommend.
Nine media organizations, including The New York Times and National Geographic, have signed a deal to distribute their content through a new Facebook feature called "Instant Articles."