Can you point to just one of those that consists of high quality downvoted comments? Certain topics seem to attract lower quality comments. I don't think a conspiracy theory is needed. I rarely see flagged comments that don't deserve it, although sometimes I vouch for flagged comments when I can't tell why they were flagged. Often they weren't even downvoted at all. Never seems to be the kind of comment or topic that makes me suspicious of a conspiracy/foul play though.