We've all heard the arguments of the drug warriors who claim legal marijuana will bring disaster. But there is solid evidence that such claims are overblown, based on the experience of states that have embraced it. For example, the advent of legal marijuana has not caused a crime wave. According to the FBI's Uniform Crime Report, there's been a slight decrease in both violent and property crime in Washington state; those numbers have basically stayed the same in Colorado. Similarly, marijuana use among teenagers in both states has stayed the same or dropped slightly since legalization.