I also encountered this rather big hole in the market. I was looking for a home security system that worked on a local private network with no outside comms, bu

I also encountered this rather big hole in the market. I was looking for a home security system that worked on a local private network with no outside comms, but that apparently doesn't exist. I ended up going with Abode without cameras or their monitoring service (self-monitored), but I'm still not 100% happy with that, since they still store all of your data in the cloud and have permission to disarm your home and so are then an attack vector I'd like to avoid. I've thought about this a lot and have quite a notebook full of ideas/notes on this: I think there's room in the market for a privacy-focused open-source home security system utilizing micro-controllers (Raspberry Pi, Arduino, Adafruit, etc.) and secure cryptographic protocols. You could make revenue assembling pre-built security sensors built from the micro-controller ecosystem, perhaps with good modern aesthetics, but the more security conscious of us could buy and build everything ourselves based on the spec for each sensor.