Perhaps the easiest form of criticism these days is to bemoan how the Internet is ruining our collective ability to be thoughtful, articulate human beings. The torrent of information and entertainment is the product of countless ‘amateurs [producing] endless streams of mediocrity, eroding cultural norms about quality and acceptability, and leading to increasingly alarmed predictions of incipient chaos and intellectual collapse’(Shirky 2010). Perhaps worst of all is the possibility that decisions formed in the midst of all this are endangering peoples’ lives, health, and well-being. On issues ranging from vaccination to genetically modifi ed food and alternative energy sources, risk communicators are grappling with unprecedented changes in how people are acquiring and sharing information. This chapter summarizes the emergence and current use of social media; the implications these networks have for participant behaviors and attitudes; and research opportunities for the risk science community.