How can access control be effectively implemented in Google Cloud services?

Implementing access control effectively in Google Cloud services is best achieved through Identity and Access Management (IAM). IAM provides a robust framework for managing permissions across various Google Cloud resources. With IAM, you can define who (users, groups, or service accounts) has access to specific resources and what actions they can perform (roles and permissions). This granular control allows organizations to enforce the principle of least privilege, ensuring that users only have the access necessary to perform their job functions, which enhances security and compliance.

Other methods mentioned may contribute to access control in a limited context but do not offer the comprehensive solution that IAM does. For example, Google Cloud Storage buckets can have their permissions configured, but this is just one aspect of access management and does not cover the entirety of cloud services. Public access links may expose datasets to anyone, thus compromising security rather than implementing effective access control. Firewalls on virtual machines help with network security but do not specifically manage user access to resources. Therefore, IAM stands out as the superior choice for establishing access control across all services in Google Cloud.