So there are multiple things you can do, and as mobbs has pointed out, there is flagawhale.

First, have your heard the expression "the whole is greater than the sum of its parts." well while this won't be true in terms of voting strengths (due to linear rewards) it is true in another aspect. If we had 1000 people flagging these posts with a diverse set of MV (or SP) then there would be no way for haejin/rancho/done/btu...etc to flag everyone backwithout destroying their VP to near 0.

Healing factor: Because they will likely concentrate their flags to the people that either A: spam more, or B: hold more SP then everyone can work together to counteract the flag and only vote enough to counteract a flag (as a reaction) in terms of both value and rep. Thus if they had happened to flag a smaller user, we could repair the damage.

Lets say we had 750 minnows with 0.00-3.47 dollar vote and lets say the average vote amongst all of them was 0.12 meaning the minnows could effective take or give $90 worth of votes, I know that is nothing compared to the whales but in the group there will be whales, and dolphins all working together and honestly, every bit helps.

I don't know, its a thought.