An approach is provided for performing cloud based computer network security services. Security policies are established for each of a number of subscribers. The subscribers are provided access to the security services via a common network cloud managed by the service provider. The security services are administered according to a multi-tenancy format, which enables the subscribers' data communications to be separately processed. The security services include network firewalling and filtering of content originating from or destined to one or more networks associated with the subscribers.