http://hnrankings.info/7609667/
Dropping suddenly from 3rd to 20th on the front page suggests some sort of penalty being applied, but is it community driven, or automated? Even with the new openness about the actions of the moderators on HN I still find some things deeply confusing.
Added in edit: This does bring home just how important upvotes are. I've seen how disproportional the effect is of downvotes on an item's ranking - one downvotes out-weights many upvotes. If you like something, upvote it, or see it sink without trace.
I think you mean flagging as there is no down voting of submissions as far a I am aware.