Consider two users: Bob browses HN and upvotes about 1000 articles a month. Jill, on the other hand, upvotes only articles she considers to be exceptional and upvotes about 1 article a month.

Should Bob have 1000 times more influence than Jill? Personally, I'd like to see what was so special about that one article Jill voted for, but a naive upvote mechanic considers it just a single vote, and is not noteworthy when compared with Bob's thousands upon thousands of votes. It would be nice is Jill's single vote was equal to 1000 votes from Bob.

Do any systems like this exist? It sounds good in theory, but I wonder how it would stand up to abuse?