This Just In: Carrying Matches in Your Breast Pocket Causes Lung Cancer!

Well, not really.  But I'd bet that if a study along these lines were conducted, a link would be found between carrying matches close to the chest and developing lung cancer.  Of course, the cause would not be the matches themselves, but what the matches are a marker for, namely cigarette smoking.  Although my example is pretty absurd and transparent, headlines similar to this sometimes appear in newspapers and on TV news programs.  If it's because the news writers truly don't understand the difference between correlation and causation or because they are more concerned with sensationalizing the news than with reporting the facts, I don't know.  But it's important to realize that popular media stories concerning new scientific research are not always accurate.  The illustration below sums it up nicely:

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