Many specialty SEO or Internet venture blogs have long covered shady SEO practices like buying links and other shenanigans. The effect on Google has been erratic--for every Techcrunch expose (think Izea), you have dozens that that go unnoticed. The New York Times changed all that.
Here's a good look at how the NYT is changing the SEO 'rules enforcement' landscape
http://www.growmap.com/nyt-google-bulldog/