Electronic Monitoring (EM) technologies have increasingly been deployed as a useful tool for criminal justice. EM has been embraced in over 30 countries worldwide thanks to its capability to contain the costs of new buildings by acting as an alternative to prison. But is this true? In order to analyse which criteria judges use in pretrial stages for the application of electronic monitoring devices, I have examined several applications or rejection ordinances of the electronic device collected in the Courts of Turin and Reggio Calabria. I have also conducted some semi-structured interviews with the judges for the preliminary investigations of the same Courts. The results of the research lead in fact to a series of critical reflections on the implementation of control technologies and on the impact they have in terms of expansion of criminal control.