The paper elaborates on several actual “dangerous fads” among youngsters and children that from early age take an active part in computer-mediated Internet communication. On the one side there is a phenomenon of fashion that has been infl uential since the early modernity basing on the novelty craze and distinction. On the other side, in the late modernity there are the advanced communication and information technologies that have brought about new and instant communication practices for the youngsters, especially in the developed world. Social media enormously facilitate various hazardous activities of youngsters in terms of mutual informing, experience sharing or even community creation around various more or less safe activities and interests. Several social networking mechanisms (contagion, homophily etc.) are presented along with the respective threats connected with the dangerous youth fads that spread easily thanks to the new technologies and advanced electronic networking skills of the youth.