I know I've been making a lot of noise about how meta-mod can be used as a tool to increase the noise.
Here's a real-world example. This post came to me for meta-modding. The moderation I was assigned to meta-mod was the one UP-MODDING the post to "Interesting". Of course I marked it "fair", because whatever moderator sacrificed a mod point for that post deserves to be rewarded.
By meta-modding that moderation as "fair", I'm helping ensure that moderator gets mod points again.
Conversely (inversely? I can never remember), there was this post. My job was to meta-moderate one of the upmods given to it ("+1 Interesting"). *YAWN* That's surely not noise. Whatever moderator used a point to mod that up surely doesn't deserve to keep his moderation ability, so I mark it "UNFAIR".
I wish I had a better example of an "UNFAIR" moderation, but you can imagine a slashbot spouting some tired anti-Microsoft FUD. When these are modded up, I mark those moderations "UNFAIR" with extreme prejudice.
In this way I'm using Slashdot's own moderation system to reward trolls and punish... well... anyone who isn't a troll.
If more trolls were to (ab)use the meta-mod system, it'd be safer for them to abuse the MOD system, and hasten the inevitable Slashdot implosion. I get the opportunity to meta-mod twice a day. It takes a couple of minutes, and I get to do my part.
NOW GET META-MODDING!