I was just thinking about this with regard to custom avatars. If one of the users of my tiny gaming site created a profile and uploaded a custom avatar, it would be published to S3. Then if they pushed their settings up to the Discourse Hub and it just copied the custom avatar URL to Wildly Popular Discourse Site™, could I potentially have a boatload of S3 transfer charges? (Yes, I realize that one avatar or background image is unlikely to break the bank … but it’s the principle of the thing … work with me here ;))