The Karma system has its advantages but the present version strikes me as a bit too crude. For one thing, a down-vote from someone who down-votes everything is not as good evidence that the post is actually bad than a down-vote from someone who barely ever down-votes anything. Also, a down-vote from a poster with lots of Karma is better evidence that the post is bad than a down-vote from a poster with lots of Karma.
My suggestion is therefore that for any given level of Karma that you have, there should be definite limit to the number of up votes and down votes you can make. If you went over that limit, your votes would get diluted, so that, e.g. one up-vote from you only would give the poster .8 Karma.
If such a system would be introduced, it would also be natural to let people give less-than-full votes (say .5 up-vote, .3 down-vote, etc).
The drawback of such a system is of course that it is more complicated, but I think it would give a better picture of what posts are good and what aren't.
There are online fora where downvoting costs you some of your own karma. That might be an effective compromise.
I like in principle the idea of weighting more informative votes more. I suppose what you'd want is that a vote counts for +/- log p where p is the fraction of the voter's votes that are the same as it. (I'm not sure whether you'd want to count "neither up nor down" as a vote for this purpose. Let's say we don't.) So if someone downvotes everything, her downvotes would be worth nothing, but then her first upvote would be worth log N wher...
To whoever has for the last several days been downvoting ~10 of my old comments per day:
It is possible that your intention is to discourage me from commenting on Less Wrong.
The actual effect is the reverse. My comments still end up positive on average, and I am therefore motivated to post more of them in order to compensate for the steady karma drain you are causing.
If you are mass-downvoting other people, the effect on some of them is probably the same.
To the LW admins, if any are reading:
Look, can we really not do anything about this behaviour? It's childish and stupid, and it makes the karma system less useful (e.g., for comment-sorting), and it gives bad actors a disproportionate influence on Less Wrong. It seems like there are lots of obvious things that would go some way towards helping, many of which have been discussed in past threads about this.
Failing that, can we at least agree that it's bad behaviour and that it would be good in principle to stop it or make it more visible and/or inconvenient?
Failing that, can we at least have an official statement from an LW administrator that mass-downvoting is not considered an undesirable behaviour here? I really hope this isn't the opinion of the LW admins, but as the topic has been discussed from time to time with never any admin response I've been thinking it increasingly likely that it is. If so, let's at least be honest about it.
To anyone else reading this:
If you should happen to notice that a sizeable fraction of my comments are at -1, this is probably why. (Though of course I may just have posted a bunch of silly things. I expect it happens from time to time.)
My apologies for cluttering up Discussion with this. (But not very many apologies; this sort of mass-downvoting seems to me to be one of the more toxic phenomena on Less Wrong, and I retain some small hope that eventually something may be done about it.)