It doesn't affect your account or access on here, and to be honest has absolutely no function in VB forum software other than to create rifts/segments between users. Much in the same way Kennel Kash has little to no use.
But I also noticed this recently. Take a squizz at my reputation!!
Pretty much there are a few people playing silly buggers, including one in particular who must think it's hilarious to give me negative feedback every week without fail with only the word "troll" as the description (you can see your rep by clicking here:
http://www.thekennel.net.au/forum/usercp.php) and scroll to bottom of page and it tells you what threads and what the comment is).
In my case obviously it's someone too gutless to raise a concern about me (with me) via PM.
Anywhoo I've got the admins looking into it for me at the moment, so somebody is probably in for a bad day sometime soon I'd imagine.