Summary spam stuffed and tagged with SEO spam.
http://googlecommerce.blogspot.com/2012/08/use-any-credit-or...
http://googlecommerce.blogspot.com/2012/08/use-any-credit-or...
This is a hard problem that no social news site has solved. One idea would be to allow users to connect stories to each other through some sort of collective voting mechanism, so blogspam submissions could be linked to each other and the primary source even after they hit the homepage.
Articles that are replies to articles should be fine, but articles that summarize other others really have to go unless they (1) do a remarkable job of shining like on the subject or (2) provide a novel viewpoint/opinion amongst the summary.
We should call seo spam summaries "spummary" or "spammary".