Throughout the literature addressing im/politeness, there is an assumed relationship between an individual, their talk or conduct in interaction, and the potential for negative evaluations of that talk or conduct by other individuals. This literature assumes that any negative evaluation of talk or conduct in interaction is attributable to the source of that talk or conduct. It remains tacitly assumed that this attribution can be made because the source is exercising their agency in producing that talk or conduct. Problematically, the understanding of agency and how it effects evaluations of impoliteness has been left unscrutinised to date. This thesis addresses this gap and explores how the effects of exercising of agency on the ways in which evaluations of impoliteness arise in interaction are achieved. The discursive turn in im/politeness research argues that the analysis of impoliteness requires the researcher to attend to the participants’ evaluations of impoliteness. That is, the analysis of evaluations of impoliteness needs to rest on the participants’ evaluations, and not those of the researcher. As such, the methodology of this thesis is to analyse the ways in which participants exercise socially-mediated forms of agency in making such evaluations. The data for this thesis is drawn from three different forms of relational networks (a closed community of practice, strangers getting acquainted, and a public social network) which are achieved across three different modes of communication (face-to-face talk, email interactions, and online polylogues in social media). The thesis is grounded in interactional pragmatics, which draws from ethnomethodology, membership categorisation analysis and conversation analysis ontologies and epistemologies to inform the analysis of the data.