It is not a purpose of monitoring but a purpose of security
http://www.kannsi.com/hidden-cameras/c-1.html
A camcorder to monitor for various camouflage camera purposes. Major uses include crime prevention, disaster prevention, measurement, recording, etc.
http://www.kannsi.com/mini-cameras/c-1_11.html
This home's hidden camera no longer worries about nighttime recording provides a wonderful nighttime experience even in the dark, so you can see the whole room in the evening. With the motion detection function, it has become possible to use for a long time. It provides dark and complete protection to see all the nightly rooms. It's always a limited spotlight view.
http://www.kannsi.com/watch-spy-cameras/c-1_13.html
Hidden camera is not a purpose of surveillance but a purpose of security.