[t0pj]

Perhaps keeping tabs on how karma is used.

Are the recently arrived users simply voting up articles yet not adding any comments of their own to explain why they've voted up?

How about this?

If a person votes up an article (which costs a point), a contributing comment by the same person can start out at 2 points instead of 1. You're basically paying back the point taken to vote up an article. This would give more incentive for users to voice their opinion instead of simply voting up (without commenting) as well as now giving others a chance to agree/disagree. If their comments don't really add any value, they'll receive bad karma as normal.

You can also show a flag next to the user id to show whether they voted for this article or not.

[joseakle]

This sounds similar to the rules Yahoo Answers has.

What about users who vote up a story so that it is stored in their history? I do it often, i like a story but don't think i have much to add to the conversation, but still want to keep it.

[t0pj]

Adding a link to your list of favorites should be functionally separated from the public voting system.

There should also be some way to eliminate the votes of individuals whom you have personally black-listed .

Thus, you could toggle between the public view of the main news page with all votes counted versus the personalized view which takes your preferences into account.

Or you could allow votes from only those you have personally white-listed.