Correlation does not imply causality. The logic is even worse when your supposed correlation is false. Today, I got an email from a friend about gun control; the email was one of those typical internet forwards. This one was about how crime rates in Australia went up after the ban (and subsequent buyback) of many types of firearms. A brief look at snopes turned up a thorough rebuttal. A simple investigation of primary sources at the Australian Institute of Criminology (AIC) shows how the data in the email was cherry-picked.