A privmsg feature, available to people who cross a karma or karma average feature, that would allow gruseom to tell people offline that their comments are dumb. Sometimes it's good to make an example of a dumb comment, but other times it just begs for an unproductive fight.
Interesting idea. That would be pretty easy to implement: it could be an ordinary comment, but that would only be visible to the sender and the receiver.
When someone points one of these issues out, I often feel bad about it. However, I usually don't edit my comment to remove or reword the offending portion because I think it's rude to the person replying and, oddly enough, those who later read it. Because they've made a good point, if I fix up my post it breaks continuity, possibly makes them sound like an idiot, and feels like I'm trying to cover up my lameness.
If I got a similar note that was private I'd feel free to make the changes without as many of those worries. Especially without concern for how they'd take it as presumably they're looking for me to shape up not score points on my misbehavior. I also think that some people that might say something are loathe to reply publicly in fear of just making it worse.
Of course it could seriously backfire if people used it just to be mean back without fear of the community observing. But it seems like it might be worthy of trying.