If a breach occurs, it's crucial to act swiftly. First, identify and contain the breach to prevent further data loss. Notify affected subscribers promptly and transparently, informing them of the steps you are taking to mitigate the damage and protect their data. It's also important to report the breach to relevant authorities, especially if it involves personal data, to comply with legal obligations. Finally, conduct a thorough investigation to understand how the breach occurred and implement measures to prevent future incidents.