Conversation so far:
What was Jon Stewart's criticisms of Fox News?
Jon Stewart frequently accused Fox News of distorting the news to fit a conservative agenda.
Did Jon Stewart have any problems with Fox News?
In November 2009, Stewart called out Fox News for using some footage from a previous Tea Party rally during a report on a more recent rally.
What happened after Jon Stewart called out Fox News for using previous footage?
Fox News show's anchor, Sean Hannity, apologized for the footage use the following night.
Are there any other interesting aspects about Jon Stewart besides calling out Fox News?
Jon Stewart stepped up his criticism of Fox News in 2010.

Question: how did he step it up?
Self-contained rewrite: How did Jon Stewart step up his criticism of Fox News in 2010?