point 1: cannabis IS a poision
point 2: never heard of a whitey?
point 3: cannabis lowers the immune system, making it easier to pick up all sorts of viruses. it can massivly damage the lungs, i know this for a fact, it litterly strips the lungs of the cila, and this can lead to emphysema after only 6 or 7 years of heavy smoking. that makes it about 3 or 4 times worse for the lungs as tabbaco. even if you consider that an average ciggy smoker smokes 20 aday and doesnt get emphysema, youve got to remember that drawin on a cig is far easier on the lungs than rippin a bong as fast as you can. also weed, if its used for long enough by an unhealthy person, can damage your heart, dont belive me, check yer pulse rate 5 mins after a big bong hit.
point 4: although there is know way that weed is anywhere as physically addicative as alcohol, any heavy smoke who has to stop smoking will get some mild physical withdrawl problems, such as innsomnia and poor appertite.

dont get me wrong guys, i love weed and hate alcohol for what it did to my mums pancreas, but it makes me laugh when people beleave with a passion that weed is so harmless