The paper explores how anonymous commentators construct and negotiate social and political identities in the specific case of Cecilia Sala, Italian journalist who was arrested in Iran in December 2024 and liberated in January 2025. We discuss how a new methodological approach, Narrative Argumentation Analysis (Magioglou, forthcoming), offering an open structure, can be used to explore how social media users construct and negotiate political identities in three key moments of the case: the arrest, the beginning of the negotiations and the liberation of the journalist. The threads analysed were both in English and in Italian and they are compared for the type of controversies they put forward. By analysing discourses around ethnicity and immigration in the context of political ideological narratives, the study provides insights into the ideological identity construction processes in the digital age. The presentation highlights how the construction of political identities can become crystallised in a binary dynamic of "In" opposed to "Out" or become more flexible through a dialogical process.