When visiting http://www.chicagotribune.com this extension will retrieve in background all the links on the headlines, and if they match content from AP, Reuters, CNN or Tribune News Services it will render those headline item blocks white, you can see them only on mouse over.
To install download the wirelessnews.xpi file from https://github.com/Laurian/Wireless-News/raw/master/wirelessnews.xpi and open in Firefox.