Because I hear horror stories about addiction to them
Because I know people personally who have suffered from addiction.
Because I am perfectly happy and serene without them (If it ain't broke...)
Because the consequences of their being illegal make life miserable for addicts
Simply because they are illegal
Other (specify in the thread if you would like)
Why do you think they call it dope, you dope?
When America is strong the world is calm, When America is weak tyrants and terrorist slaughter the meek. ~ SgtRock
Psilocybin Mushrooms - Effects - by Erowid
Brown University - Psilocybin
Basically it sounds as if the long-term effects can be taken as positive or in rare cases, extremely bad. The effects are very random and it is suggested that you take them under supervision.
"An error does not become truth by reason of multiplied propagation, nor does truth become error because nobody sees it." - Gandhi
There are lots of legal drugs I choose not to take because of potential adverse affects.