I think it would be nice to have the ability to attach tags to user profiles. Private ones.
So I can mark the user as a troll
and next time I see his replies - I don't even start talking to him.
(Yes, I've been attacked by some troll for the second time today)
Java-hater
for example. To know in the future that it is not a good idea to discuss him about java. I've got bad mood today after the talking to that troll. How moderator supposed to protect me from that? Well, they arent. The best way was to not even answer him, but I forgot who he is and made that mistake :-(