As far as I can tell, all three replies to that comment were made before it hit -3.
(I know that my reply was made with no penalty, and Yvain's reply was already there at the time; wedrifid's later comment also suggests that his reply wasn't penalized.)
Has anyone yet mentioned or reported that for the last couple days, the "karma for last 30 days" is showing zero for everyone? And that we no longer can see the top contributors for the last 30 days either?
Do we have an explanation or estimation for a bugfix on this?