Of course, the 'Feds' maintain that weed is the source for crime ,
violence , rape , is highly addictive ,
and is the stepping stone to other harder drugs. (That's because of the element & environment of those that dispense/sell it)
At one time in the past, it was not illegal, and Rx'd by doctors.
Today, Obama has put it on Federal 'hold' and will let the states mandate the degree of prosecution, or to ignore it. (But its still on the books as a Federal crime to possess, or grow and the DEA is champing at the bit, to bust anyone they can.)