A method, system, apparatus, or computer program product is presented for routing event messages between data processing systems based on privacy policies associated with the data processing systems and based on event policies associated with event types for the event messages. When a system attempts to publish an event message for a particular type of event or to subscribe to those event messages, an event policy is checked to determine whether the system may publish messages for that type of event or may subscribe to those messages. Moreover, if a publishing system publishes an event message that contains personally identifiable information for a user of a data processing system, and a subscribing system has subscribed to event messages having the same event type, then the privacy policies associated with the systems are compared to determine compatibility or incompatibility between the privacy policies before routing a message between the systems.