Is it the landlord's job to prevent a tenant from using facial recognition in the tenant's area of the building? I think the tenant is in charge of putting up the disclaimer if the tenant does that.

As for facial recognition in common areas, the landlord can put a clause in the lease agreement requiring tenants not to do that.

If disclaimers are required for facial recognition and a UPS driver has a facial recognition bodycam, I assume it'll be the UPS driver that needs the disclaimer, not every place the UPS driver visits.