Oh James, you must be a republican.  People need to be controlled and are incapable of running their own lives?  :-)

Come on Marijuana has been around since the beginning of time, in fact it was made on the third day of creation by God.  This is far different from stronger, man made drugs, such as Crystal Meth or Heroin.  These drugs increased in popularity after natural substances such as pot and mushrooms were outlawed.  A big mistake as stronger, more powerful drugs were soon developed.  

Actually the impact of marijuana on the individual is known.  Its impact is far less than say alcohol or tobacco or a lot of legal drugs.  Stop supporting big government and start supporting the individual.