In rebut GM's do stuff if the scenario is right. I was doing limit break in crawlers nest killing exorays with my linkshell mates for a good half hour (no competition, fast kills, good shit) when outta the blue this asshat dragoon shows up and starts spamming shouts how red mages suck and he's ubor dragoon that can outvoke us yada yada.
He proceeds to voke the majority of mobs in the exoray camp for the next half hour, following our thief around, voking when she went to pull etc etc. Eventually his backup comes and they all apologize for him but don't do anything to stop him besides that really. So I call the fucking GM lol. I tell him he's ruining my gaming experience. Check the logs, we tried to be nice and said "hey there's enough for both to share no need to be an asshole about it and voke anything that comes our way" and of course he laughs and keeps doing it.
Long story short I put a gm call in, [gm]Hermetica - "I hear someone's stealing your mobs" -- that right there says "I'm not going to do anything for you if it's not claimed you have nothing" -- so I tell him he's ruining my gaming experience by insulting my party, following our puller, and making it impossible to get the quest finished. I say check the shout and say logs. He says ok, 5 minutes later they're banned from crawlers nest. ALL of them, him and his pals. We get our drop 10 mins later uncontested. It's all a matter of DID they actually break the user agreement? If no, you don't have any grounds to complain.