New datapoint on mass downvoting:

Sometime between this comment and my last comment, approximately all of my comments were downvoted exactly once. Seems kinda strange.

(I don't have anything that I want to post to Main prepared anyway, so karma's kinda a moot point, but I hoped this could be helpful if anyone ever does look into it, and times are included in downvote logs.)

Edit: Hehe! And within ten minutes, this one joined the rest of them...