A Thoughtful look at Marijuana Legalization?? This article is Biased is an understatement. Most people who smoke stay home and do it. I've never seen a violent pot smoker, and I am 100% sure if there was marijuana in someone's system in the ER that it was not the ONLY drug in their system. Traces can be detected up to a month after use but the effects only last a few hours after use. This whole article is a big pile of anti-cannabis propaganda. Probably pushed through one or more of the many Powerful groups lobbying against cannabis. Big Paper, Big Cotton, Big Oil, Big Pharma, Big Tobacco, and Big Plastics all have a reason to hate cannabis/hemp. Hemp produces a superior product with less of an environmental footprint.