This is a cool idea, and I have no interest whatsoever because cloud.
If I could just wire it into my home network and keep everything on hardware I own and operate, it’d be much more palatable. (I’d have to worry about somebody hacking my guestbook-cum-occupant-log-cum-exterior-network-access-point, but that’s a lesser concern for now.) But having a complete list of everyone who stops at my doorstep, along with a constantly available photo/video stream, sent over the Internet to servers I neither own nor control and which are an incredibly juicy target to every burglar who’s ever been introduced to the concept of casing, is right out.
The link has basically no technical information as well.