It's a shame this happened, but good of you to air the problem on here so that something may be done about it - at least you now know what to do if it happens again. Our officers are very diplomatic, but do not take this kind of thing lightly as it degrades the game/experience for everyone.
Personally I only use Vent when raiding/guild events, or when listening to teams going for bosses/etc that I am interested in. The main reason I don't actually use Vent is that Vista hates me and really hates my headset. But that is my problem
Hopefully this was a one off, and these individuals were just getting something off their chest.