Sadly this isn't possible on Digg, though it would be interesting if they provided a page with the most buried or hated stories. After all, just because you don't like a story doesn't mean it is spam, but it is still news.
Jack Spirko has knocked together an interesting site where your story can appear on the front page because it is "hated" and I feel the idea is worthy of a mention.
You can see that currently the hated stories seem to only appear in the sidebar – I would love them to be integrated with the main results by default
