The social web has brought two major changes in the way online content is generated and consumed: a) everyone can generate online content, and b) this content is available to everyone else in the world immediately. This real-time flow of information has proven to be a powerful means of increasing awareness and mobilizing support for humanitarian and political causes around the world. However, the same channels of information can be misused to spread rumors, lies, and suppress free speech. In my talk, I will focus on two such examples that our research at Wellesley College has uncovered: spreading misinformation during an election campaign for the U.S. Senate, and suppressing citizen reporting of the narcotraffic conflict in Mexico. The long-term goal of this research is to design, develop, and test computational solutions to the problems of information reliability and trustworthiness of sources in the social, real-time web.