There is no reasonable way to interpret this other than as having a stalker.
Suppose we find the list of users who downvoted your recent comments, and there are fifteen users on that list, each of whom is an active poster in their own right. What conclusion would you draw from that?
(It may be that, when we actually find that list, there is one account, or a handful of mostly inactive accounts, that represent almost all of the downvotes, in which case 'stalker' is a reasonable conclusion. But it's not the only way the data could turn out.)
And the solution to how not to catch false positives is to use some common sense.
Common sense is costly. The point to doing this algorithmically is that you get a query result that says "these are the twenty cases that might be karmassassination" instead of "these are the twenty thousand cases that might be karmassassination" or "these are the zero cases that might be karmassassination."
It's also not particularly wise to run this check just on people who complain- part of the point of this is to prevent karmassassins from driving users away, which hasn't happened to the people who stuck around to complain (somewhat)- and at least a few users have a habit of downvoting any comments complaining about karma loss because they don't like comments that complain about karma loss, and so they'll be extra likely to show up on that list.
Suppose we find the list of users who downvoted your recent comments, and there are fifteen users on that list, each of whom is an active poster in their own right. What conclusion would you draw from that?
I'd conclude that this is an extremely weird statistical anomaly which is not one user moderating down comments, but looks almost exactly like it is. One user doing a lot of downmods has to apply the downmods to separate comments, so his downmods are spread out. 15 users producing the same total number of downmods independently of each other would p...
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.)