Weed. Good or Bad? Safe or Unsafe? Should it stay illegal, or become legal? And what about hemp?

When answering this, please try and use all the scientific facts you can. I don't want to hear any propaganda. For instance, old school propaganda used in the 30's, which people actually believed, were things like, "marijuana is the most violence causing drug ever", "if frankenstein came face to face with a marijuana smoker, he would drop dead of fright". Or more propaganda or ignorant views like Nixon had on this matter, for instance he is quoted in saying, "I want a Goddamn strong statement on marijuana, I mean one that just tears the *** out of them. You know, it's a funny thing, every one of the s that are out for legalizing marijuana is Jewish." ...yeah, obviously this guy had some warped views to begin with...