You want to make sure that your organization’s Cloud Storage buckets cannot have data publicly...

Uniform Bucket-Level Access: Enable uniform bucket-level access for all your Cloud Storage buckets. This feature ensures that access control is applied consistently at the bucket level, simplifying management and improving security.

Domain Restricted Sharing: Enforce domain-restricted sharing through an organization policy. This policy ensures that only users within your organization’s domain can access the data in the buckets, preventing public exposure.

Policy Enforcement: Apply the necessary IAM policies and ensure that no buckets are configured to allow public access. This combination of settings ensures that data in Cloud Storage buckets remains private and accessible only to authorized users within your organization. References:

Google Cloud - Uniform Bucket-Level Access

Google Cloud - Organization Policy Service