There's much we don't know about what the 21st Century will bring. But we’re not just flying blind. We know that certain things matter more now than they used, and others matter less. One thing that matters a lot is the Internet. It has transformed how we learn and how we connect, and how we come together. In China, there are now more than 600 million Internet users — about twice the population of the entire United States. With the advent of Chinese social media, starting about a decade ago, they began to connect more, speak out more, challenge the government more. The government has responded by clamping down, especially since Xi Jinping came to power almost three years ago. If a big country like China, with big aspirations, places significant limits on how its people can use the Internet, does that also limit its potential to be a 21st century power? Seems a good question to be asking, as Chinese president and Party Chief Xi Jinping arrives for a state visit, and speech at the United Nations.