Transmedia products are becoming a usual practice in media, and they incorporate both professional contributions and user-generated contents. From this point of view, we propose a legal, comparative and transnational approach to the legal implications of copyright laws to transmedia products. We focus on news items and informative products. Participative or citizen journalism, fan fictions, which appeared in several media, has developed the so called transmedia narratives, and the law necessarily faces some problems derived from their particularities. Since the international trend of copyright is rather aligned with a strong approach which presumes that authors should be remunerated, or receive any compensation, for the successive exploitations of their works, we explain which is the impact of copyright (and, in general terms, intellectual property) in the distribution of both moral and exploitation rights, and more specifically transformation rights and derivative works. The legal trends towards digital single market in Europe, copyright law reforms in the United States and the particular situation of the United Kingdom in this respect will be considered.