Police/security could be called on a resident every time they walk into the hallway of their building, and landlords would tell them "we've put in a support ticket with our facial recognition vendor, we'll let you know their response in 4-6 weeks".

Or residents could be locked out of the building with no way to get in for weeks at a time.

Just facial recognition wouldn't have a point - landlords are going to use this data for something, and that something is likely to interfere with residents quiet enjoyment of their residence.