The rise of social networking sites in the 2000s has as its downside created avenues for online hate speech and online hate groups varying from groups of white extremists to groups glorifying school shooters. A preliminary reading through online hate literature led to a discovery that the previous literature consisted of multiple overlapping terms and meanings of online hate. In this paper, a literature review was conducted to clarify these different discussions. The alternative concepts of online hate were distinguished based on a sample of relevant articles from various different academic fields, such as law, sociology, communication, and computer science. The selected articles were analyzed using conventional content analysis techniques. This paper is a part of an ongoing research project focusing on the issue of online hate. It was found that in the selected articles the vague use of words and lack of clear concepts was common. However, few articles utilized existing definitions that were for example legal or prepared by online hate watchdog organizations. The findings underline the importance of transparency when defining the subject matter of a research. Studies concentrating on the actual experiences of online hate are being encouraged.