RARELY has a thumbs up led to such bad feeling. Back in 2009, Justin Rosenstein created Facebook's "like" button. Now he has dedicated himself to atoning for it. Rosenstein's voice is far from a lone one. A decade ago, society was wide-eyed at the possibilities of social networks, web search, smartphones and online shopping. The Google motto "Don't be evil" expressed a prevailing optimism about how the internet, and the companies shaping it, would create a better, more open world.
展开▼
