This chapter delves into the ambiguities of the expression of online hate speech and seeks to understand the challenges it raises for researchers. It discusses cyberhate against migrants in its multiple dimensions, i.e. as a manifestation of the affective publics of the Internet, crystallising the social and political dimensions of a representation crisis constructed as a public problem. Cyberhate in the context of migrations towards Europe builds upon the divide “us/them”, “them” alternatively designating migrants as a group, or those who allegedly support them, i.e. politicians, media, scientists and other designated elites. Hate speech draws on representations and shared meanings, community building and otherness and profits from the ecosystem of the Internet.