Backstory: I recently moved into the city, from the burbs... opposite, I know. Ironically enough the facebook group from the burbs erupted over the weekend with mass burglaries. Neighbors noted that some had video evidence of the burglars running off. Someone suggested a group/crowd based security camera system, intriguing.
The Idea: Allow others in your community to view and use your outdoor security cameras. This could help track burglaries, theft and non criminal activity such as lost pets.
Deep Dive: The companion app and nextdoor are community based neighborhood apps, interfacing with security cameras would solve this. Ring has started this idea but a third party that connects ring and other security cameras would be perfect and not restricted to one type of hardware.
Validation: There was a quite lengthy thread in our old community facebook page about people wanting this app. Similar apps in this space exist that prove users will pay to feel safe.
Monetization: You could charge a small monthly fee but give it for free for users who allow their camera to be used by the community. Once you gain adoption, you could reduce it to a discount.