Extant research on public sector digital transformation has emphasised the process of deliberate digital technology use by public organizations in pursuit of efficiency and innovation. Studies of the unintended or contrarian uses associated with digital technologies have been scarce. This study explores a case in which parents of schoolchildren in the City of Stockholm react to the perceived poor usability of a learning management system through citizen “hacktivism”. The parents developed a challenger app on top of an existing platform, to which the city reacted by trying to obstruct development work, both technically and through litigation. We interpret this as a case of digital transformation reconfiguration through boundary object tuning, legal tuning and digital transformation tuning. These lead to, respectively, reconfiguration of 1) the site of transparency and engagement, 2) the boundaries of responsibility and ownership and 3) the locus of control over public services. We contribute to the public sector digital transformation literature by offering tuning as a way to understand (re)configuration of the non-linear and dialectical and materially embedded process of digital transformation. We also empirically explore the phenomenon of citizen hacktivism, offering insights into associated processes and effects.