The aim of this thesis is to investigate how use-practice and social context can inform how we understand Twitter data, through a qualitative research approach to the hashtag #dkgreen. The thesis is based on three digitally driven hypotheses, that we try to offline ground through 10 conducted interviews with Danish Twitter users. With a fundamental understanding of our Twitter data and Twitter technology, we were able to produce a collection of qualitative empirical data that can contribute to a heightened situated understanding of the #dkgreen space. Through a postphenomenological approach it was possible to support our framework of understanding, by investigating how the #dkgreen mediates sustainability debate, based on the relationship between its users and the technology. Based on our collected analysis and discussion, we conclude that there exists a central composite relation, between the #dkgreen and its users, which involves a hybrid of human and technological intentionality, which together affects how the debate in #dkgreen is mediated. It is emerged that the platforms infrastructures and user practices together form a digital space, which forms a type of public. The hashtag #dkgreen facilities an opportunity for interaction with politicians, decision makers, media and prominent users who are all interested in the 'green agenda'. This contributes to how #dkgreen mediates a power that enables users to influence the ongoing debates and interpretations of sustainability. On the basis of these relationships, we argue that the interactions that take place in sphere of #dkgreen are political and thus form #dkgreen as a political hashtag public.