I've gotten sufficient evidence from support that voiceofra has been doing retributive downvoting. I've banned them without prior notice because I'm not giving them more chances to downvote.
I'm thinking of something like not letting anyone give more than 5 downvotes/week for content which is more than a month old. The numbers and the time period are tentative-- this isn't my ideal rule. This is probably technically possible. However, my impression is that highly specific rules like that are an invitation to gaming the rules.
I would rather just make spiteful down-voting impossible (or maybe make it expensive) rather than trying to find out who's doing it. Admittedly, putting up barriers to downvoting for past comments doesn't solve the problem of people who down-vote everything, but at least people who downvote current material are easier to notice.
Any thoughts about technical solutions to excessive down-voting of past material?
Same technical solution I always offer: An upvote or downvote should add or subtract the number of bits of information conveyed by that vote, conditioned on the identity of the voter and the target.
In the simplest version, this would mean that if person X upvotes or downvotes everything written by person Y, those votes count for nothing. If X upvotes half of every comment by person Y, and never downvotes anything by Y, those votes count for nothing (if we assume X missed the comments he didn't vote on), or up to 1 bit (if we assume X saw all the other comments).
Better would be to use a model that blended X's voting pattern overall with X's voting on Y's posts and comments.
I'm not sure what the exact mathematical proposal here is, but I shall guess the following rule: If X has voted positively on Y p times out of n votes so far, if X's next vote is an upvote it will confer a karma score of -log((p+1)/(n+2)), and if it is a downvote, log((n-p+1)/(n+2)). X voting positively on each of Y's n posts will give a total karma of log(n+1), negatively on everything gives -log(n+1). Logs are base 2. Votes never count for nothing, because X's votes on Y so far are only a sample from which we cannot conclude that X will vote with certai... (read more)