The Privacy Commissioner has expressed concern that landlords are compiling and sharing information via Facebook to blacklist unwanted tenants. This is in breach of a tenant's right to privacy.
As a landlord, you are justified in collecting personal information about tenants or prospective tenants such as proof of their identity, whether they have any pets and information to determine if they can pay the rent. However, you are unlikely to be justified in collecting information about their nationality, marital status, gender or banking history. Do read our article on the 'KFC test' in the Spring 2019 edition of Property Speaking here.
Now that it is more difficult to remove an unwanted tenant from your rental property, it is crucial to do your due diligence on a prospective tenant. With that in mind, you must remember that tenants have the right to privacy and, in doing your due diligence on a prospective tenant, you can only collect information which is actually relevant to assess their suitability as a tenant.