I play on a pve server so this isn't normally an issue, the few times I've had issues I've made notes of their names. If I see someone flagged I generally try to jump in and have some fun... often I die, and then when I rez I useually go on my way... the other day this skull warlock kept after me for about 8 rez's... Reaganmagoo will remain on my KOS list for quite some time... assuming I got the name right, it didn't show up on armory the day he was after me, and it doesn't show up now...

I double checked the spelling but I suppose it could have been Reagarmagoo or something similar and I missed it.