I see what your saying. I just think smoking one blunt on a weekend is no where near as bad as smoking a pack a day. But regardless, if we're talking banning unhealthy habits, start with diet and lack of exercise. As far as weed being discovered on dealers, your examples didn't really indicate marijuana had a causal effect on them committing their crimes. It's like saying "every drug dealer I've ever arrested had pants on, therefore we should ban pants"