Why Fox News is less to blame for polarised politics than you think(economist.com)
economist.com
Why Fox News is less to blame for polarised politics than you think
http://www.economist.com/blogs/lexington/2013/03/media-and-political-polarisation
http://www.economist.com/blogs/lexington/2013/03/media-and-political-polarisation
edit: Another interesting comparison is how a news site like Hacker News (or even Reddit) reaches a decline in the content being provided. Reading the commenting/posting guidelines offers an interesting insight into how HN tries to prevent that decline from happening.