Well it's okay to negative rep those who deserve it, but if you're doing it because you disagree with them or you just don't like them, that's not right.
Of course, it really doesn't matter anyhow because it's just a green bar really...it's not a big deal or anything.
Well, if I look at mine, it isn't always made of random reps. Some are, because we feel like it and some aren't. But, you know what? Everyone has their rights to do it. I sometimes feel nice and give rep without comments just to boost them up. It doesn't really matter as just having more rep, doesn't mean you actually know the true person who types this stuff.
I usually try to keep up a spirit from back in August 2005.
i like to think the rep bars mean how much that person has helped the forum to grow, but that's not the case here..at least it keeps up the moral on the forum.