The report spam does sound interesting and it was mentioned before who is to say what is not related content?
Webmasters could easily harm their rankings by reporting sites that they do not see as being quality sites or relevant links, however, Yahoo could see that site much differently. Subsequently rankings could suffer as a result.
I took 10 words from the first sentence on my site. I personally wrote that sentence in 2003. I searched Yahoo for that exact phrase, 60 results returned.
These are also in SiteExplorer
Every one(on everyone) of those sites are either MFAs, layered(on layered) with nothing but bluntly Scraped content on it, Or Redirects to parked domains including a call to popup(on calpop) that says that indeed "The ¦.¦eds are cheap".