我们被无限的媒体网从四面包围，如何能够确保最准确的信息脱颖而出、并且引起注意？在本书中，凯斯•R. 桑斯坦对于积蓄信息和运用知识改善我们生活的人类潜能，展示了深刻的乐观理解。
在一个信息超负荷的时代里，很容易退回到我们自己的偏见。人群很快就会变为暴徒。伊拉克战争的合法理由、安然破产、哥伦比亚号航天载人飞机的爆炸——所有这些都源自埋于“信息茧房”的领导和组织做出的决定，以他们的先入之见躲避意见不一的信息。领导者和普通人如何能够挑战思想偏狭的决策，接近人类知识的总量？
许多以互联网为基础的、令人震惊的分享和聚合信息的新方法有助于公司、学校、政府和个人不仅获得、而且创造不断增长的准确的知识。通过不断激动地自动修正数据，覆盖了从政治、商业计划到体育运动、科幻文化的维基，积聚并精炼着信息。开放资源软件使得许多人参与到科技发展之中。预测市场聚合信息，允许公司（从计算机制造商到好莱坞工作室）做出关于产品投放和职位空缺的更优决定。桑斯坦证实了，人们如何能够消化聚合的信息，而不必遭受信息爆炸之痛——何时以及为何新的聚合技术是如此惊人的准确。
在一个正见和八卦日益难分伯仲的世界里，许多头脑聚在一起上网的努力可能会提供最好的通向信息乌托邦之路。

What happens to democracy and free speech if people use the Internet to listen and speak only to the like-minded? What is the benefit of the Internet's unlimited choices if citizens narrowly filter the information they receive? Cass Sunstein first asked these questions in 2001's "Republic.com". Now, in "Republic.com 2.0", Sunstein thoroughly rethinks the critical relationship between democracy and the Internet in a world where partisan Weblogs have emerged as a significant political force. "Republic.com 2.0" highlights new research on how people are using the Internet, especially the blogosphere. Sunstein warns against 'information cocoons' and 'echo chambers', wherein people avoid the news and opinions that they don't want to hear. He also demonstrates the need to regulate the innumerable choices made possible by technology. His proposed remedies and reforms emphasize what consumers and producers can do to help avoid the perils, and realize the promise, of the Internet.

In this follow up to Republic.com, his first appraisal of technology's effect on public discourse, University of Chicago Law School professor Sunstein waxes pessimistic about today's "nightmare" of limitless news and information options-and, more significantly, the limitless options for avoiding it. Gravitating toward those newspapers, blogs, podcasts and other media that reinforce their own views, citizens carefully filter out opposing or alternative viewpoints to create an ideologically exclusive "Daily Me." The sense of personal empowerment consumers gain-and subsequently equate with "freedom"-only fuels the "echo chamber" effect, which replaces a sense of democratic unity with accelerating polarization. Sunstein argues that the most obvious dangers of this effect-single-minded terrorists and hate groups who use cyberspace to communicate directly with receptive audiences-hide the more subtle and far-reaching consequences of the "growing power of consumers to 'filter' what they see": not only do diverse publics need to hear multiple voices, they also must cultivate a culture "where people actually want to hear what others have to say." This perceptive volume effectively illuminates the contradictory impulses at the heart of the citizen-consumer, demonstrating how "there can be no assurance of freedom in a system committed to the Daily Me"; though challenging and thought-provoking throughout, Sunstein's chapter of partial solutions proves underwhelming.