The moderate conservative blogger Conor Friedersdorf wrote a blog item detailing a supposed example of "epistemic closure" on the right. He claims his examples show right-wing pundits crowing over the ACLU failing to intervene in a case when, in fact, they had intervened; this was supposed to prove that right-wingers didn't bother checking unfiltered sources of information. However, the ACLU's intervention is dated the 10th and their blog item about it is dated the 11th. Most of the example conservative complaints pre-date this response, so they don't support Friedersdorf's point at all. There's something parallel between Friedersdorf lazily failing to check the dates and just assuming they support his point, and his targets' lazily failing to check the ACLU and just assuming its actions support their point. He is, commendably, less vitriolic and unpleasant in his error.
The example complaints that predate the ACLU's response: Stop the ACLU, Limbaugh, News Real Blog, the Pirate's Cove, the Old Jarhead, Jules Crittenden, Radio Voice Online, Uncoverage, Waiting for the Other Shoe to Drop
The example complaints which are actually examples of "epistemic closure": the Bakersfield Californian, Speak Now America, the Mighty Righty forum
Unknown: the Millennial Perspective
UPDATE: Friedersdorf responded in his comments, pointing out that these sites (and radio entertainers) haven't updated or corrected their posts. That's a good point.