i'm fascinated by this stuff (professor david nutt was sacked from the advisory council on the misuse of drugs by the then health secretary, alan johnson, specifically for criticising the re-upgrading of cannabis to a class b drug, and more generally, for telling the truth about drug-matters in a way that contradicted the government policy). we live, most of us, safe in the conviction that our lives are guided by rationality and common sense, but when these are contradicted by strong emotions the latter trump the former every time. paradoxically this usually happens when we are talking about people who seem to have abandoned rationality and common sense and given into strong emotions: drugs, sex, crime...

http://www.guardian.co.uk/society/2010/nov/01/alcohol-more-harmfl-than-heroin-crack