Information and communication technologies (ICTs) have empowered non-state social actors, notably, social movements. They were quick to seize ICTs in the past (printing presses, television, fax machines), which was a major factor in their successes. Mass email campaigns, blogs, their audio- and video- variants (the podcasts and the videocasts), social networks like Facebook and MySpace, and other tools, such as Twitter, are increasingly popular among the movements and their activists. The extremely rapid diffusion of new technologies has raised a lot of questions about their impact on many areas of life from macroeconomic consequences to interpersonal relations, including much comment on their impact on social movements. Social historians are even rethinking the whole history of media. However, up to this point, we have no broad view of how social movement organizations are making use of the media. What types of movements are making use of new media? In what way are they using them and for what purposes? Are they more common in younger organizations, or in organizations that operate on larger geographic scales? Does their use lead to a sense of democratic empowerment? To answer these questions, this study analyzes an internet-based survey of four populations of social movement organizations ranging from the local to the international in geographic scope (four specific populations analyzed are: Pittsburgh (USA), Poland, the international movements, and the movements with high visibility online). This dissertation explores the use (and the non-use) of ICTs in the first broad survey on their use by modern social movements. It provides a broad overview of the movement's demographics (location, range, goal) and their membership (size, activity). It details the diffusion and use of over twenty ICTs, analyzing the success stories of email, static websites, phones and social networking, as well as the relatively poor performance of blogs, podcasts and faxes. Primary research questions revolve around the blurring boundaries between members and non-members (unofficial supporters and volunteers), the use of new media (by whom and for what), and the consequences of those trends (such as opposition to professionalization, or the empowerment of activists). [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]