IMO, yes they do. Everyone points out the most valid point and that is the deterrence factor - that is huge. However deterrence is normally an external/outside factor. If someone ignores that and enters a structure internally/inside then what? These type of cameras provide someone an option to place cameras in areas where you want to monitor things possibly without the sight of a standard camera. For example, use of these cameras in a personal residence in a living room, dining room, kitchen, hallway etc are great. They can be concealed very easily and provide you the insight/coverage you desire. However, they will not make visitors (family, friends) feel un easy while visiting or in the home. Regardless if recording or only for monitoring the sight of a camera makes some people uneasy and you don't want to do that to your family or friends while inside there "home", just the bad guys should have that uneasy feeling, which the exterior cameras should do. Some people don't care about the sight of a camera in there home, and for those, the mini domes or moreso the recessed mini domes are great, for others covert cameras offer a great alternative solution to see what they want without seeing the hardware. Sure there are trade offs like IR avalibility or coverage and quality for the price compared to the alternatives, but only the end user can weigh those options.