The servers on which zones are hosted aren't especially vulnerable. The firewall was added to protect the biller, not to protect the server on which it resides. Yes, DDOSes became an issue at one point, but that was (as I recall) after the firewall had already been put in place. Ghost Ship kept saying he was waiting for SSC approval before giving it to us. Once he gave up waiting, we got it fairly quickly (meaning only a few weeks).