The revelation of the surveillance practices of the US National Security Agency (NSA) and the UK Government Communications Headquarters (GCHQ) serves as a compelling case study of the new agenda-setting capacities in the 21st century. We use a stream of 14 million messages on Twitter to note how its reach equals that of television. Next, we demonstrate the interactive communication characteristics of social media in the use of hashtags, retweets, and shared URLs. Finally, we draw upon data from Lexis-Nexis on newspaper stories and broadcast transcripts to emphasize the different ways social and mainstream media constructed the story about surveillance and interacted with each other. We conclude agenda setting can no longer be understood as a monopoly of the mainstream media, indexed to the actions of political elites. Social media, through its reach, interaction, and broadening of ideas brought into the discussion, emerge as a distinctive mode of large-scale communication. Giving voice to the people introduces an entirely new dimension to agenda setting.