I propose special badges for frequent downvoting.
Downvoting means you sacrifice your own reputation to fight spam and low-quality questions. People who do so make contribution to community, so that spam will be punished.
Badges could be for example:
Punisher - 100 downvotes (silver).
Inquisitor - 500 downvotes, at least 25% of them on votes with reputation -2 or less (gold)
Additionally, for people, who mostly downvote:
Malcontent - at least 100 votes, 50% or more of it downvote (bronze)
Judge Dread - at least 1000 votes, 50% or more of it downvote (gold)