V roce 2015 se na internetu v České republice zvedla vlna nenávistných projevů proti migrantům, zejména muslimského původu. Tento článek prezentuje výsledky výzkumu nenávistných projevů vůči migrantům a uprchlíkům na Facebooku v České republice v létě 2015. Za pomoci kombinované metody analýzy využívající automatický sběr dat a následnou manuální triangulaci výsledků bylo možné odpovědět na některé základní otázky o procesu vytváření a šíření nenávistných projevů na Facebooku. Je zřejmé, že vlna nenávistných projevů proti migrantům v roce 2015 byla cíleně i nezamýšleně podpořena společnými aktivitami různých uživatelů Facebooku (především mužů ve středním věku příslušejících ke střední střídě), propagandistickými aktivitami extremistických skupin, zpravodajstvím masmédií a také designem samotné komunikační platformy., The increased influx of refugees and migrants to the EU in 2015 has been followed by a noticeable presence of online hate speech against migrants in many countries across Europe. The article presents the results of a study of hate speech proliferation on Facebook in the Czech Republic during the summer of 2015. Its goal is to identify the producers of hate speech and determine their social background, explore the main channels of hate speech proliferation, determine the specific groups of migrants targeted by hate speech, put the hate speech in the context of online political communication, and discuss the role of media and politicians in the process of hate speech proliferation. With regard to the works of Castells, Skocpol or Bennett and Segerberg, online hate speech can be perceived as an extreme variety of new, rapidly evolving modes of political communication as such. Social and political activism has been shifting from membership-based organizations and parties towards flexible movements and initiatives with strong emphasis on the logic of identity politics. People may or may not engage in hate speech production as lone independent actors, but they still perceive their actions as part of larger collective efforts. When we focus on hate speech as a form of civic activism or networking, new interesting patterns can emerge. The study is based on a mixed-method analysis; computer-assisted data collection via the Social Insider software tool was further triangulated by random sampling and subsequent manual coding and analysis of selected Facebook posts, comments and other content. The question of reception and influence of hate speech was largely omitted from the analysis, due both to the research methods chosen and to the inherently cyclical nature of social network communication. Hate speech itself was identified according to a custom-made definition based on various existing legal definitions and scholarly perspectives of legal and media science. The results of the analysis indicate that the wave of hate speech against migrants was aggravated both intentionally and coincidentally by the combined forces of disparate Facebook users, extremist groups´ propaganda, news media and the design of the social network itself. As for the social background of frequent producers of hate speech, there was a strong prevalence of middle-aged and middle-class males, and a significant under-representation of both elderly and young Facebook users. The majority of the hate speech content was produced and spread in small-scale communication exchanges, i.e. under articles posted on individual user profiles etc. The communication activities of larger, well-organized populist groups, political parties or communities were visibly present, but they did not play a significant part in the hate speech production itself - although their possible involvement in agenda setting cannot be underestimated. All the datasets indicated that a vast majority of the hate speech in the given time period was aimed either against migrants in general or Muslims, while these two groups often overlapped. The role of mass media and of the design of the Facebook platform in the entire process should be discussed further. It became apparent that the producers of hate speech themselves seldom created any substantial shared content such as articles or videos. To the contrary, many hateful comments occurred through sharing and subsequent discussion of articles produced by online news outlets. As the Czech mass media are defined by transformation, uncertainty, layoffs and disintegration of professional routines, this creates a dangerous mix that could lead to further proliferation of hate speech., Matouš Hrdina., and Obsahuje bibliografii