Social movement studies are an interdisciplinary, multifaceted, and broad field transversal to different social and human sciences, which has been growing and consolidating since the late 1970s. Since then, and concurrent with the intensification and pluralization of protests and protestors around the world, the recognition and establishment of social movement studies inside different areas has accompanied the recognition of social movements as legitimate social and political actors. This variety and diversification of perspectives and object of study has helped to include some 'hidden' forms of protest which are particularly relevant outside Europe and USA, and specially in authoritarian and semi-democratic countries. Despite this, the fie...