Controling hosting? in Developer Help
In addition to what both of the other two have said, you can use version checks as a safeguard. In Align Four, and if I recall, every other game I have out on the hub, I implemented a version check at world/New. It'd check world.version against the version on the hub. If they didn't match up, it'd delete the world. The only problem with this approach was that sometimes the version check would stop working and report the new version (world.version matching the version on the hub) as being outdated. I believe it has something to do with updating of the game, because the version check then worked correctly if I removed the game from my pager and added it again.