  Internet of things (IoT) technologies are becoming a more and more widespread
part of civilian life in common urban spaces, which are rapidly turning into
cyber-physical spaces. Simultaneously, the fear of terrorism and crime in such
public spaces is ever-increasing. Due to the resulting increased demand for
security, video-based IoT surveillance systems have become an important area
for research. Considering the large number of devices involved in the illicit
recognition task, we conducted a field study in a Dutch Easter music festival
in a national interest project called VISOR to select the most appropriate
device configuration in terms of performance and results. We iteratively
architected solutions for the security of cyber-physical spaces using IoT
devices. We tested the performance of multiple federated devices encompassing
drones, closed-circuit television, smart phone cameras, and smart glasses to
detect real-case scenarios of potentially malicious activities such as
mosh-pits and pick-pocketing. Our results pave the way to select optimal IoT
architecture configurations -- i.e., a mix of CCTV, drones, smart glasses, and
camera phones in our case -- to make safer cyber-physical spaces' a reality.
