"Free breach monitoring" usually means "we eat the cost until we can't." Here is how @XposedOrNot@infosec.exchange stays free: Google Cloud with Datastore for the breach index, Cloudflare in front for caching and abuse handling, and a codebase you can read end to end. The expensive part of this problem is curation, not serving. Serving your slice of already-compiled breach data costs close to nothing at the edge. The code is public. If it earns it, a star helps others find it: https://github.com/XposedOrNot/XposedOrNot-API