Can you recommend current work that deals with the production of multimodal content, including the translation of content produced originally in Arabic, by activist groups?
I'm not sure whether you mean just the production of multimodal content or also the translation of multimodal content; if the latter, then Mona Baker's recent work on activist subtitling in the Egyptian Revolution would be relevant. See e.g. the link below, or her book Translating Dissent.