FWIW (btw, please 'scuse if this message looks funny, I'm on lynx at the colo right now....) many, many, many, broadband nets are very insecure.
It'd be rather trivial for me, from here, to drop a NIC into promiscuous mode and see traffic on the entire local loop. Now, decoding it, that's another story, at least for me, as that's not something I am either "into" or do for a living.
You should never say anything on the 'Net that you don't want indexed by Google. That goes for any protocol, although there are some that are, basically, 'safe'.
IRC/AIM isn't one of them....