I for one would like to see a minimum ratio of upvotes to downvotes as a measure to mitigate abuse. That is to say you "earn" a down vote for each upvote you cast.
Additionally I think the ratio of downvotes to upvotes you give should be public on your profile, and an admin tool should be available to Magazine administrators to block voting, posting new threads, etc. Based on a user's vote ratio.
This is a behavioral problem with clear mechanical fixes.