Is Diane Tianhua's access card illegal?

Not illegal. It is reasonable and legal to set up access cards in the community. Community is not a public road or public place open to the outside world. Setting up access cards in the community is only an effective management for residents in this area. Residents in the community have access cards and can allocate property. The owner can't make a key card without permission. It is against the property management regulations for the owner to assign the key card privately. If things in the owner's corridor are seriously lost, you can call the police.