The best way to tell how dangerous any given drug is is to look at the ratio of effective dosage to fatal dosage. If two aspirin relieve a headache, how many kill you? If half a joint gets you laughing, how many would it take to put you under? This chart shows the ratio for many of the most common recreational drugs.
As you can see, just 5X the normal dose of heroin or 10X that of booze will kill you, while you'd need to take 1000X the normal dose of LSD to do the job, and the only way smoking marijuana would kill you is if you lit your hair on fire or ended up drowning face-down in a tub of ice cream. An interesting article explaining how these calculations are made can be found here.
So, if it's true that pot, mushrooms and LSD are utterly NOT dangerous, what do we call the hundreds of thousands of people currently sitting in prisons across the US, convicted of cultivation, possession or sale of these substances? People who not only did not hurt anyone, but COULD NOT have hurt anyone by their actions inasmuch as these substances are simply NOT medically dangerous?
I call them political prisoners.