My dad was just telling me that at work people intentionally subscribe majordomo lists to other majordomo lists, and worse, majordomo + their SMTP servers are dumb enough to loop messages infinitely. Heh.
I wrote a list server in high school ... it ruled. 5 points to the first person that can reply and remember its name. 5 extra points for its second name, and the reason we had to change it. :-)