PurposeThe Italian government addressed the first wave of its COVID-19 outbreak with a series of social restrictions and calculative practices, all branded with the slogan #istayathome. The hashtag quickly went viral, becoming both a mandate and a mantra and, as the crisis played out, we witnessed the rise of the Italian social movement #istayathome. This study examines how the government's calculative practices led to #istayathome and the constituents that shaped this social movement.Design/methodology/approachThe authors embrace social movement theory and the collective identity perspective to examine #istayathome as a collective action and social movement. Using passive netnography, text mining and interpretative text analysis enhanced by machine learning, the authors analysed just over 350,000 tweets made during the period March to May 2020, each brandishing the hashtag #istayathome.FindingsThe #istayathome movement gained traction as a response to the Italian government's call for collective action. Thus, people became an active part of mobilising collective responsibility, enhancing the government's plans. A collective identity on the part of the Italian people sustained the mass mobilisation, driven by cohesion, solidarity and a deep cultural trauma from COVID-19's dramatic effects. Popular culture and Italy's long traditions also helped to form the collective identity of #istayathome. This study found that calculative practices acted as a persuasive technology in forming this collective identity and mobilising people's collective action. Numbers stimulated the cognitive, moral and emotional connections of the social ties shaping collective identity and responsibility. Thus, through collective identity, calculative practices indirectly influenced mass social behaviors and the social movement.Originality/valueThis study offers a novel theoretical perspective and empirical knowledge to explain how government power affects people's culture and everyday life. It unveils the sociological drivers that mobilise collective behaviors and enriches the accounting literature on the effects of calculative practices in managing emergencies. The study contributes to theory by providing an understanding of how calculative practices can influence collective behaviors and can be used to construct informal networks that go beyond the government's traditional formalities.