charitable causes throughout the years. by every metric, facebook is a success. its revenue in 2018, $55.8 billion. it was just 272 million in 2008. but facebook at 15 faces complicated questions, a ripple effect of zuckerberg's mission. is what's good for business good for society? and what is the cost of connecting the world? >> right now the tech industry has been telling themselves this narrative that if you connect people, platform for free speech is automatically good. i think the deeper upgrade we have to make is a philosophical upgrade, which is what does it mean for these things to be good? >> facebook is a living, breathing map of society. and it's literally a map of every single person in all of the relationships and all of the interactions between all those relationships. and so, in a way, it's as messy and human as we all are.