Perhaps a simpler (for the HL) solution may be for Agoracom to invent another level of "flag" requiring that two people are required to validate a thumbs down of a post. This will not stop the coordinated team of negative posters but if a single person votes for the thumbs down - it would require a different poster to "verify" the thumb down for it to have an effect on the points. Perhaps naming the thumbs down voter would aid the Hub in vetting the ones with large thumbs.

Of course the validated thumbs down maybe should be allowed to be over ridden by say 5 thumbs up from viewers. This may give the forum a checks and balance approach for regular viewers to keep coming back.