As the fediverse grows, moderators and administrators will need tools to help with moderation. In particular I propose to send all posts to X. X can determine if a post should be blocked before it is distributed via ActivityPub. I propose an architecture in which the origin server makes a single call to X, and then relays an attestation to all recipient servers. The recipient server can then check the attestation and decide whether to accept the message, without requiring additional calls to X.