Here in Spain we have a very famous blog among journalists called Malaprensa. It show the biggest mistakes of the spanish journals, all made by not double-checking the data or just not to think twice the things we're writing.
Thanks to infosthetics I could know that there is a blog on the same style, but focused on charts. That place is Junk Charts.
You can find examples of every kind, finding little (and most of the times not so little) mistakes on media that we use to consider sometimes half-gods instead of infographics journalists, as NYTimes.com. Or champions of the rigor, as The Economist or The Guardian.
Sometimes you can agree or not with the author's point of view, but it's a good place to visit before making our next pie.