Some time back, I wrote that I was unwilling to continue with investigations into mass downvoting, and asked people for suggestions on how to deal with them from now on. The top-voted proposal in that thread suggested making Viliam_Bur into a moderator, and Viliam gracefully accepted the nomination. So I have given him moderator privileges and also put him in contact with jackk, who provided me with the information necessary to deal with the previous cases. Future requests about mass downvote investigations should be directed to Viliam.
Thanks a lot for agreeing to take up this responsibility, Viliam! It's not an easy one, but I'm very grateful that you're willing to do it. Please post a comment here so that we can reward you with some extra upvotes. :)