Where exactly did you study math? Even a relatively low-level monk - let's say level 8 - has over a dozen votes per day. If you make less posts than he has votes, he can downvote every single thing you post, and given that your average post rating even if you post relatively good stuff is often low (mine is slightly over 4, even excluding this thread), he can kill as much as a quarter of your rating just by himself. And he'll get rewarded for doing it. It's just extremely annoying to be on the receiving end and be told the mods know who it is but won't tell you or do anything about it.
For the same reason, I think anonymous posting should be eliminated. People troll anonymously whenever it's a topic they think will risk their precious rating, then use their account to downvote anyone who disagrees with them.