Ooh you could do all that and instead of a flat out denial based system fall back to a fingerprint scanning doorbell. Probably a weird conversation to have in the pub "Alright lads I'm gonna need you all to scan your fingerprints for me"
I already wrote a system that can take new facial inputs, classify you as "new user", and put your data in a database. All you need do is go up to the door. I can easily view the timecode and enter your details (name, phone#, email) at a later date.
