The No. 1 reason people get arrested in the U.S. is for violating drug law. More people are arrested for drug-related crime than for any violent crime, including drunken assaults. Of all drug-related arrests, 82% are for possession, and more than half of those are for marijuana. Basically, the war on drugs winds up being focused on marijuana possession, despite the fact that it is less addictive than other illegal drugs and is not pharmacologically linked with violence or overdose the way alcohol is.
These arrests not only take up an enormous amount of police time but also are extremely expensive: one estimate put the costs at $10.7 billion. And for what? There is no relationship between arrest rates and rates of drug use or addiction.