Hoaxy is a joint project of the Indiana University Network Science Institute (IUNI) and the Center for Complex Networks and Systems Research it aims to provide visualisations of fake online fake news stories with visualizations of how they spread. For instance search the site for Trump to view a range of stories including Trump meets with Goblins! These give dates with charts showing the sources spreading via Twitter in a specific data range. Good for research conspiracy theories and rumours online.
Another good example is this case study from the New York Times
For more background on why this is believed to be necessary try the recent Reuters report on fact checking sites in Europe
And see the brief article from Politifact which labelled fake news as its lie of the year.