Not sure if legally it would be considered to violate privacy.

My guess would be the mentioned privacy is relating to the dwelling itself, that is, the landlord can’t come hang out in your living room or hide cameras in your apartment.

Plenty of apartments have 24/7 concierge at the front door and monitored entrances. That isn’t considered violating privacy even though the concierge can see you come in and out.

Would a computerized system that does the same thing necessarily violate the legal definition of privacy ? I suspect it would be hard to tell at this point.

I think once you start documenting and recording exactly who is coming and going and exactly what apartment they're going to you are violating privacy.

No doubt cases like this will be tried as people test the bounds of that legal definition.

I don't think so. I know many gates cominities that have a guard that verifies identity for those comming and going from the subdivision. And logs are kept.

If you can hire a human to do it and it is fine then I don't think any automated systems would be violating privacy.

Also there is no privacy in public places and you can probably conclude that you are in a public place before you enter. Eg. Their is no privacy at the checkpoint.