Latch is a leading vendor of internet-of-things "smart" doorlocks that are in increasing use in rental housing (the company claims 10% of all new multiunit construction incorporates their product); they allow entry by keycode, keycard, and Bluetooth.
Latch says it doesn't actually use any of the information it gathers, and isn't actually sharing the data that it reserves the right to share, and has promised to revise the policy, but companies come and companies go, and leadership changes, and firms pivot (recall that for Facebook's first ten years, the company billed itself as pro-privacy and promised never to spy on its users).
Centrally controlled, building-wide smart locks are also a powerful tool for landlord harassment. A tenants' rights group in Hell's Kitchen claims their landlord is using the telemetry from smart locks on common areas to monitor which tenants are participating in meetings to address their grievances with the building's management, and is targeting those tenants for harassment in an attempt to force them out of their homes.
Additionally, IoT door-locks represent juicy targets for hackers, and are vulnerable to things like botched over-the-air firmware updates, like the one that bricked the front doors of 500 Airbnbs in 2017.