possible AIM dos?

[John Scimone <jscimone () cc gatech edu>]

After reading this outdated article regarding AOL Instant Messenger's "warn" 
feature:

http://www.attrition.org/security/denial/w/aim-warn.dos.html

I began to wonder what type of restrictions were put on it.  Does anyone know 
what is stopping someone from registering multiple screen names, then sending 
warnings from each of those names, all targeted at the same user thus keeping 
that user at a 100% warning level denying them the instant messenger service 
for the most part? 
any thoughts are appreciated.
thanks.

John Scimone