Slashdot back in the day (say circa 2000) had the karma problem. First, people would post snarky comments to get points for being funny, so Malda, Bates, et al.

Slashdot back in the day (say circa 2000) had the karma problem. First, people would post snarky comments to get points for being funny, so Malda, Bates, et al. stopped counting "funny" towards karma. Then people started posting group think, all just to see their numbers go up. So /. capped karma at 50, which was beyond the point where you actually accrued any benefits for having good karma. Eventually they moved to a labeled five point likert scale. Apparently that stopped the nonsense since there literally was nowhere to go beyond "excellent". HN could probably do something similar and mitigate karma ranking.