I'm a brazilian and I watched it. There were two major IRC networks in Brazil. The older and bigger with more users was Brasnet, the younger, smaller and with less proficient users was brasirc later renamed to redebrasil.
IRC in Brazil was mostly born on university campi but, by the second half of the 90's it quickly attracted teens who simply wanted to chat. Our version of the Eternal September.
Most used OS at the time was win9x and most used IRC client was mIRC. Actually, most users didn't know the difference between mIRC and IRC. So, it was very very unsafe for illiterate users. Self-reproducing mIRC scripts and people trying to fool others with netbus and the like was extremely common.
One day, by the end of the 90's, both major networks joined. The service quality went deeply down. Operators of big channels lost their status, illiterate users flooded the network and traditional brasnet channels got filled with users from redebreasil who weren't used to the established netiquette. To make things worse, redebrasil had advertisements and such ads went together with them when they joined brasnet.
That day was one of the saddest days of my life, that day I lost my operator status on #programacao on brasnet, I was 15 and getting that status was no easy task. It was the day I stopped using IRC in Brazil.
The thing just went downhill from there. Getting IRCop status was reason to act arrogantly, attacks were rampant and winxp came along been not much safer than win9x. Netsplit was common because of the attacks, bots tryied to fool people to shady and phishing sites, there was no control to stop abuse from IRCops...
Then, by the beginning of the 2000's IM became more popular, then social networks. Actually MSN messenger and orkut popularity were major blows in brazilian IRC. New people buying computers to get connected no longer even knew about the existence of what was once a major entertainment communication medium.
The quality of the service didn't improve, and users started migrating away from it. It commercially devalued, ISP's didn't want to host it and, in 2007, brasnet was closed: http://www.brasnet.org/2007/05/era-uma-vez-o-irc-brasileiro....