Let me see, is the main thrill of creating abusive usernames being
that people will see them in recentchanges? Well if so consider
https://bugzilla.wikimedia.org/show_bug.cgi?id=18364
"array of boring event types to exclude from recentchanges".
P.S., I tried to add the above to
http://techblog.wikimedia.org/2009/04/planning-to-tighten-torblock-restrict…
but it seems that is just a blackhole, and the way to reply is via this
mailing list.