Unrestricted Firebase Browser Key Triggers €54K Gemini API Bill Overnight

A misconfigured Firebase project with exposed browser-accessible API keys led to rapid exploitation of Gemini APIs, accumulating €54,000+ in charges within hours. This incident exposes a critical gap in Firebase's security defaults and highlights how AI service integrations can create unexpected cost amplification vectors that cloud providers may refuse to cover, underscoring the need for stricter API validation and billing safeguards.