There is not much we can do at this point. His accounts do not post anything and everyone is free to upvote/downvote whatever they see fit best. One thing the community can do is to support each other, when such downvoters appear (clvr is not the only one).

If you should see any good posts that have been flagged by them to zero payout, just add a link to this comment and I will try to compensate the losses.