Anyone who is heavily into anything will be harmed by it. People addicted to coffee, people addicted to food and become obese and can't move, people addicted to work and therefore have no time for other endeavors such as raising theier kids, and so forth. If you take anything to the extreme it is gonna be harmful. On the other hand for the casual smoker the risks are nil. I would say that many people find inspiration when stoned that otherwise would not find. Musicians, painters, writers, there are logs of their use of weed and the ideas that got while stoned that otherwise would have never entered their minds. It is an gateway to a different line of thought (for people that are inclined to thinking, that is), and it is in no way a path to hard core drugs in the least. People who use heroin, cocaine and somesuch frown upon weed smokers. The fact that it is illegal in many countries means shit, the fact that it is legal in others and stats prove that there hasn't been an increase in usage or in so-called weed_related_incidents (whatever it means) proves that legalising MJ would be the thing to do. It is readily available as it is, so what is the big deal? In some countries cops don't give a damn if you walk past them smoking joint, they know that it doesn't lead to violence and/or acts of vandalism. Unlike alcohol which when used irresponsibly almost always leads to violence and in many cases death. No matter what, if people want they will do it, restriction wont bring anything. So tax it. :D