So since I really can't stop playing this game, I've tried to come up with a way to keep track of the jerks I come across. I used to use DiggKarma which allowed you to rate players and keep notes on them. On a simple mouseover, I could tell if this was the idiot who begged me for runs through Scarlet Monastery or was a kill-stealer. But Wrath broke DiggKarma and that made me very sad.
I finally just HAD to find something similar. And it is Vanas KOS. Yes, it is primarily meant for PvP servers, but it works wonders for someone like me who just wants to play alone AND keep track of jerks. Some of the features of this add-on:
Add players, or even guilds, to a "Hate List" or "Nice List"
Allow messages to come through a raid-type warning and in the chat log and in a warning box whenever someone is in the area doing anything
Mouseover shows info on player that you may have added
I am LOVING this add-on. It tells me in bright red when there is someone around I want to avoid(I am pretty sure it gathers data from the combat log as well as mouseovers). I don't play on PvP servers(not anymore anyway), but this is an excellent add-on for someone like me who wants to avoid trouble(as well as most other people).
If you are looking for an add-on of this type, I highly recommend this one.