[pedalpete]

This is true, but shouldn't it be fairly easy to develop a system that looks for these groups of voters and discounts the total volume of their votes, rendering their gaming of the system as moot?

Also, seeing as discussion is so important to HN, I assume that active discussion is just as valuable as votes. I'll often comment on an article but forget to upvote it.

[jacalata]

Actually, hn has a "controversy" penalty that automatically downgrades posts with more comments than votes (kicks in at 40 comments) and pushes them down or off the front page.