Hemp?

It is fairly common knowledge that hemp is a versitile material with an almost bottomless list of potential applications.

Can someone tell me why, in the wake of massive deforestation and the huge associated environmental impact, we are still making paper/other materials out of trees?

200 years of growing, just to be cut down and used to make The Sun - what an insult - when hemp, obtained from the cannabis plant, can be sowed and harvested just weeks later, and could seemingly solve a lot more social problems than it would cause.

A friend referred me to this documentary, http://www.youtube.com/watch?v=PSKJrgGqx_E which I have not watched yet - I am led to believe it sheds some more light on the issue.