Chapter 5 is about the mobilizing structures of demonstrators and their impact on the strength of motivation to participate in demonstrations. We focus in particular on the channels of participation in demonstrations. We examine the role of direct (interpersonal networks) as well as indirect (media) channels and whether they differ depending on the national context, the issue of demonstrations, and the type of demonstrators. Concerning interpersonal networks, we look whether demonstrators were asked to participate by different types of networks. More generally, we confront two competing views of recruitment to social movements: a view assuming that demonstrators make an independent choice based on their motivation to become active and a view maintaining that they are brought to them mainly by other actors.