This paper explores impoliteness-related discourse on Facebook as a form of expressing situated moral judgement. The analysis focuses on negative and aggressive comments as a response to one public post that claims the non-existence of Australia. The content of the post indicates the threat to national identity of anyone who associates themselves with the country. As a result, a large number of impolite comments were made. A qualitative analysis of the dataset (limited to one month from the post’s publication) reveals four main strategies that are used in order to express the judgement of the post’s inappropriateness and repair the wrongdoing. Those range from insults of the author’s mental abilities and suspicion of drug use to violence-related discourse (e.g., death threats) and counter-attack of the author’s national identity. This paper, thus, aims to contribute to a growing area of research into online impoliteness. Keywords: situated moral judgement, impoliteness, CMC, Facebook, wrongdoing, face, national identity