What I find most sobering about this is that it sounds like were it not for the defacement 6 days after the hack, no one would ever have been any the wiser. I

What I find most sobering about this is that it sounds like were it not for the defacement 6 days after the hack, no one would ever have been any the wiser. I know that DB-level and web-server-level intrusion detection systems exist - can the HN community comment on what might have detected this particular attack (even if only after-the-fact?).