Not a hack for once, just an annoyance.
The OS X IRC client Colloquy has what I consider a big privacy issue. It bothers me that they don't seem to recognize this as a problem, when pointed out.
When you create a new IRC server connection, Colloquy will automatically put your real name (as entered into OS X) into your details, for anyone to see.
The big privacy issue is that this happens "below the fold" – you don't see that your name is there unless you expand the detailed settings.
Many people want some level of anonymity on IRC. IRC clients should either not divulge personal information such as the real name by default, or make it very clear that they are doing this, so that you can change or remove it.
Thus, in my opinion, either the detailed settings should be expanded the first time you create a connection (and it could, perhaps, remember your expanded/contracted setting thence) so that users notice that it includes their real name; or the real name should not be automatically entered.
Anything else violates (at least my) user expectations of privacy.
I've discussed this in their IRC channel and posted in on their bug tracker, but the response is that it's been discussed before and they are not changing it. Pah!