Listinfo page disabled?

I’ve got some discussion lists hosted on my domain. When I try to go to the listinfo.cgi overview page, I get the following message:

"This overview has been disabled. Please browse directly to the specific list’s listinfo page. To visit the general information page for a list, open a URL similar to this one, but with a ‘/’ and the list name appended.

If you are having trouble using the lists, please contact the list manager."

It’s helpful to have this overview page so my users know what lists they need to join. Any idea why it’s disabled?