This chapter investigates virtual linguistic landscapes (VLLs) from ‘below’ by exploring (potentially) multilingual practices on social media. Due to the participatory culture of social media, resulting in user-generated content, users may construct the linguistic landscape (LL) of the networks in which they engage. This study examines the diversity of languages used in tweets about the European Day of Languages (EDL)—an annual event organised by the Council of Europe to highlight and promote linguistic diversity as well as the importance of language learning in Europe. A corpus of Tweets (N = 50), compiled from the official EDL hashtag (#coeEDL), is both quantitatively and qualitatively examined using a coding scheme for hashtag analysis. The tweets (i.e. semiotic signs) were analysed for language visibility and saliency in the corpus. Initial findings show the dominance of English in tweet composition, along with a ‘symbolic multilingualism’ in added modalities. While the latter confirms the potential of Web 2.0 platforms for multilingual representation, the former must be evaluated critically from both linguistic and (socio)technical perspectives. Although diverse user practices and motivations determine the multilinguality of bottom-up VLLs, their experiences of those same VLLs are partly determined by platform algorithms. This has implications for virtual knowledge experiences, and may be explored via classroom pedagogies.