IMSI and WiFi Catchers can be implemented within and around buildings of importance such as embassies, ministry buildings, palaces, security forces buildings etc....
IMSI and WiFi Catchers can be implemented within an airport site to monitor incoming and outgoing travellers to support intelligence activities and national security initiatives....
IMSI and WiFi Catchers can be implemented within a prison/correctional/detention centre to monitor for contraband cell phones, which is allowing criminals to continue their illegal activities whilst incarcerated and serving a criminal sentence....