The deniers on Twitter. The No Mask groups and their communication

The Sars-CoV-2 pandemic caused millions of deaths all over the world but, despite this, a lot of people still claim that the virus does not exist. This implies a huge problem public health is at stake. In this paper we aim to analyse the way deniers communicate on twitter. 6th 2021. After collecting tweets in 5 waves, through Social Network Analysis measures, we observed the features of networks. Then, taking into account the weight of the "retweet count" index, we selected the first 10 tweets for each extraction. Once the tweets were selected, they have been analysed by means of both cluster and textual analysis. Analysis of the most representative groups of the various networks showed that communication in November was rather unstructured. It did not generate a network but rather self-referential messages. The second wave shows a network with greater aggregating power. In the groups in the third wave, we may notice a mobilization with very limited distance between vertexes which implies a redundancy of information. The fourth wave, instead, highlights an increase in the number of groups, despite the reduction in the number of vertexes. Finally, the fifth wave has four groups with a limited number of nodes.