Abstract:The focus of this paper is on the nature and role of online aggression in larger scale societal tensions and its interaction with the use of humor. The study analyses expressions of online aggression in different online environments. The study involves content analysis of online media from discussion forums and less regulated social media like blogs. The material was gathered for a research coordinated by the Ministry of Justice in Estonia, and it covers the time span of eight years: 2000-2007. The discussion addresses three types of sources in particular (1) anonymous comments (2) thematic forums and social networking media, and (3) blogs. This allows for insights into how anonymity affects the contents of electronic utterances, including the degree of aggression in them. We aim to describe the phenomenon of online aggressiveness in general: its extent, content, and context. Attention is given to how verbal aggression on the Internet goes hand in hand with banter, or friendly teasing. An overview of the flaming/ joking patterns in the commentaries leads to the questions on how humour is embedded in Internet flaming, and finally to the dynamics of "us" and "them" in the material. In this way, the paper touches upon the very narrow and hard-todefine line between aggression and humour.