I just came across this graph today, showing a correlation between crime victims per 1000 citizens and the release of some of the most criticized computer games (numbers taken from the US Bureau of Justice Statistics). I have been an avid critic of dubious correlations myself, but I thought this graph illustrates a nice point nonetheless (please note, however, that the graph is skewed since it starts at 20 instead of 0, thereby exaggerating the effect -- a strategy too often seen in media and politics).
As usual, XKCD puts it nicely:
