We are studying how an inherent dialogue structure is formed by the conglomeration of an Internet opinion article as a source text and its anonymous comments. We are using methods of conversation analysis and membership categorization analysis, originally intended for the analysis of coherent spoken dialogues. A source text and its comments can be considered as dialogue acts and commentators turn out to be dialogue participants. Every commentator can react to the source text or to some of the previous comments. A dialogue is formed by occurring a ‘bunch’ of many micro-dialogues. On the other hand, the commentators are categorizing themselves as well as agents of the source text. As a result, an additional structure layer is formed. The coherence of turns is also structured non-linearly.