We have technology. The state-of-the-art filter (Akismet) catches 99.9 percent of the spam posts. Still working on trying to stop the .1 from getting through. It is not a WSB-unique problem; other forums around the Web have it worse.
We watch the admin end when awake and catch many pretty quick but at some point we do have to sleep for a few hours (I made one last round before taking a nap 3-5:30 am). Nothing has been “wiped out”; it just got temporarily pushed down.