An amount which is large to me, but thanks for trivializing my willingness to sacrifice.
While I'm genuinely not sure whether that's tongue-in-cheek or not, either way I'd rather go to Reddit to witness such tragicomedies and not see this community, too, devolve into adolescent internet-points-bickering. I admit that I dig the entertainment value (and the bait is strong), but as the proverb goes, let's keep this place free from apotheosing imaginary constructs. Instead, right this way is a better place to bravely martyr yourself for the public good.
It is my estimation that none of the people around here whose approval is typically sought will actually judge you by your karma score in any significant sense, as opposed to by being impressed with the content of your comments, or your posts in Main. There are plenty of low karma commenters whose contributions I respect, and some high karma commenters whose I don't. YMMV.
I'm just tired of the signal pollution, and would like to be able to use karma to honestly appraise the worth of my articles and posts, without seeing 80% of my downvotes come in chunks that correspond precisely to how many posts I've made since the last massive downvote spree.
EDIT to add data points:
Spurious downvoting stopped soon after I named a particular individual (not ALL downvoting stopped, but the downvotes I got all seemed on-the-level.)
One block of potentially spurious downvoting occurred approximately one week ago, but then karma patterns returned to expected levels. I consider this block dubious, because it reasonably matches what I'd expect to see if someone noticed several of my posts together and disagreed with all of them, and did not match the usual pattern of starting with the earliest or latest post that I had made and downvoting everything (it downvoted all posts in a few threads, but not in other threads), so I'm just adding for completeness.
Spurious, indiscriminate downvoting started up again approximately half an hour ago on Sunday (12/1/2013), around noon MDT.
Edit: And now on Tuesday, 12/3/2013, at 10 AM, I'm watching my karma go down again... about 30 points so far.
Edit: And now on Saturday, 12/14/2013, at 2 PM, I'm watching my karma go down again... about 15 points so far, at a rate of about 1-2 points per second.