The paper aims at analyzing Internet mechanisms impact on shaping processes of ‘places of memory’ and ‘communities of memory’ among Lublin and Bialystok inhabitants. Compared are memories presented as official urban portals with unofficial memories reflected in social networks and Wiki-articles. Mechanisms of memory constructing are discussed regarding group memories that reflect presentation in official and unofficial internet-sources of Jewish communities’ position in Poland and relationships between Polish and Jewish population in both cities.