The book builds on the work of scholars who have noted that social movements changed their shape and focus in the 1970s to become more top-down and professionalized. In the book, I point out that one of the reasons for this shift is that the means of communication changed dramatically.Grassroots groups used to have to organize into what has been called a “trans-local” structure—local chapters or nodes connected to a larger, national structure. Many groups in the 1970s began to organize in more of a top-down manner and were no longer built into local chapters. I argue in the book that one of the reasons for this was that a new technology came on the scene around this time—the ability to create computerized mailing lists—and this allowed a more centralized, professionalized structure. Groups abandoned the trans-local, grassroots approach that mobilized around face-to-face encounters.I argue further that, with social media, it is certainly possible to continue this model of organizing but I highlight a number of contemporary case studies where advocates are utilizing social media and other tools to recreate the grassroots, face-to-face organizing of prior eras. They are also rebuilding social capital and trust, two essential ingredients (and by-products) of grassroots, face-to-face organizing that were more common in grassroots movements of prior eras, before the advent of the computerized mailing list.