A Main site Moderator to me? What it means? A MSM is a person who keeps the main site in check, and under all regulations given, enforcing the 'law' and trying to have the site the site it should be, weeding out people who just come to make things worse. The purifiers of the website; those who make everything the way it should be. This job is important, as there are many kids on this website, and without proper moderation, they would be terribly influenced and hurt (emotionally) by people who shouldn't be there. This can be proven; if you go up to a kid in 6th grade, for example, where I am, they'd be able to speak about things they should not have learned, and talk the way they should most certainly not talk. Nobody needs more bad influences, and the MSM's job is to enforce this and help the website be friendly as well; to have a good influence.
The MSM has the power to remove/censor comments anywhere on the main site. This can be used, and should be used, to moderate messages around the MS, to keep them clean of things inappropriate that could affect anyone, such as the things you know are inappropriate, and are probably thinking of when I said 'inappropriate', right..?
And on a sidenote, I have limited knowledge of the powers of the MSM, but I got some help from others / the other people who've posted in this thread. Sorry about that, but anyway,
the MSM also has the power to ban. This is a stricter punishment and regulation to the people on the MS who don't follow the rules and do something bad. This is a CRUCIAL job, as there are the people who do bad things to an extent where censoring all their comments is not enough, and a ban is required. However, this sometimes is a dangerous job, as banning a member who did nothing wrong is not great at all. This is the same with issuing warnings, which is self-explanatory, it's a warning to the person who did something wrong.
When I would use these powers? Anytime I see an inappropriate post, profile description, username, game, or anything else. I assume the MSM's will have to do like a patrol every now and then, going around the MS searching for inappropriate things, like a policeman lurking around the city searching for a murderer.
To sum up, the MSM is an important job, and even though if he/she doesn't have to do much work, the very presence of the badge he/she bears acts as a sign; "I am an moderator. Be careful bad guys, i'm on a lookout." c: