Eliminating dupes from reddit

Here's a way reddit could fix the problem of repeat posts of the same story: introduce optional meta-moderation, a la Slashdot.

1. First, the system would have to cache a copy of the target page of every link submitted to reddit.
2. On regular pages, where lots of stories are listed, there could be a small text link on each story that says "report repeat".
3. When you click it, the system would show you a list of all reddit stories that contained a link url that is the same as any link url on the target page of this story. You look through them and put a checkmark next to all stories that you think are basically the same as this one.
4. On the reddit top-level menu, there is a section called "earn karma". When you go there, it shows you a list of stories that were checked as being similar by another user. You are asked to indicate whether the other user was correct (and the story is a repeat) or incorrect. You are not shown the user's name.
5. If you indicate correct, the user gets a small boost in karma, and the original repeat submitter gets a small cut in karma; if you indicate incorrect, the user gets a large cut in karma.
6. To prevent vandalism in the form of a mischievous user cutting others' karma, you are cut off from the "earn karma" section for a period of time if your rate of disapproval of others' similarity opinions is far above average.
7. But if your ratings are more or less close to the mean, you earn karma which gives stories you submit a boost.
8. And in the future, other fun ways to earn karma could be introduced to the "earn karma" page, perhaps randomized. Users would get addicted.

This way,

1. users have an incentive to fairly rate others' reports of repeat submissions
2. which means users have an incentive to report repeat submissions accurately
3. which means repeat stories are detected
4. which means users have an incentive not to submit repeats.
   

The best thing is that the system, like Slashdot's, could be voluntary and unobtrusive. And unlike Slashdot's, you won't need to spend time researching the context; the context, in the form of the similar previous story submissions, would be put there for you to see.

Best of all, such a system would be a great advertising trick to snipe Slashdot users away from Slashdot: no more dupes!