Tribal Fusion's PageGuard is a multi-layer security system that provides brand-safe advertising by ensuring ads are only served on approved domains and safe pages. PageGuard uses real-time contextual analysis and filtering at the page level to determine the topic and safety of a page before serving ads. It also verifies domains and filters out unsafe content categories like nudity, violence, or illegal activities. PageGuard provides 100% visibility of ad impressions and full integration with Tribal Fusion's ad serving system to prevent unsafe ads from being served.