Sunstein's 2006 book, "Infotopia: How Many Minds Produce Knowledge", explores methods for aggregating information; it contains discussions of prediction markets, open-source software, and wikis. Sunstein's 2004 book, "The Second Bill of Rights: FDR's Unfinished Revolution and Why We Need It More than Ever", advocates the Second Bill of Rights proposed by Franklin D. Roosevelt. Among these rights are a right to an education, a right to a home, a right to health care, and a right to protection against monopolies; Sunstein argues that the Second Bill of Rights has had a large international impact and should be revived in the United States. His 2001 book, "Republic.com", argued that the Internet may weaken democracy because it allows citizens to isolate themselves within groups that share their own views and experiences, and thus cut themselves off from any information that might challenge their beliefs, a phenomenon known as cyberbalkanization.