Same reason we put on a seatbelt when we go for a drive.
> In order to let neighbors who might not have seen the letter know what was potentially coming, five tenants convened in the lobby of one of the two buildings on a late October morning to spread the word. A few days later, those five tenants — like most of the residents at Atlantic, black women — received a notice from property management with pictures of the gathering taken from a security camera; they were told that the lobby was not “a place to solicit, electioneer, hang out or loiter.”
> New York State law, in fact, grants tenants the right to meet peacefully in nearly any location in a building as long as they are not obstructing passageways. Management maintains that tenants were getting in the way even if the pictures did not clearly indicate that.
Why are you jumping to the conclusion that is has to go this way? Very possible that a landlord would be happy to simply have someone log a face and then go back to that person if there was a particular and legal reason to know who the face was. Now sure if they wanted maybe they could google image search the face and find out who it was. But per my other comment there is nothing to prevent a building owner (landlord or otherwise) from installing a camera and filming everyone that enters a building and actually even posting that face on the internet for everyone to see. (Would not go down very well of course but it would be legal as it's a public place). If you want to hang out in front of Shake Shack (arbitrary) with your camera all day and take pictures of everyone who enters and buys a burger or a shake you can do that.