This paper, based on the ongoing research activities of the project DIGINAUTS, presents an effort to study migration-related social media resources, which we define as Migrant Digital Space (MDS), across four European countries (Greece, Germany, Denmark and Sweden). The paper will first describe the process and challenges of “mapping” MDS before proceeding to show how the collected data variously reflects critical incidents offline, thereby suggesting that the data could serve as a useful resource to study the interplay of human movement and ICTs, as well as serving to illuminate hidden aspects of Europe’s recent history of migration which, reaching a peak of influx of migrants in 2015, acts as a background for the paper.