Weed isn't harmless either. While the media has grossly exaggerated the dangers of marijuana, it would be a great inaccuracy to say it does "nothing." Anything you burn is by nature carcinogenic and therefore harmful, plus, virtually every single reputable scientific source, textbook, and organization including the American Lung Association is in unanimous agreement that marijuana isn't harmless. It is going to take a lot more than personal blogs, third party sources, and references to but no direct source to alleged scientific studies saying otherwise to convince me that the entire scholarly consensus is wrong. Either way though, it's kind of irrelevant. Who cares whether or not tobacco and marijuana are harmful? Or if one is harmful and the other isn't? It is my body after all and if I want to harm it, who are a bunch of stoners to tell me I can't? As long as I harm no one else it's really no one else's business. Besides, the health risks of tobacco can significantly be decreased by using only snus imported from Sweden--where it's steam pasteurized to reduce TSNAs and regulated as a food product--or by using organic tobacco.