"The costs of this national obsession, in both money and time, are astonishing. Each year, enforcing laws on possession costs more than $3.6 billion, according to the American Civil Liberties Union. It can take a police officer many hours to arrest and book a suspect. That person will often spend a night or more in the local jail, and be in court multiple times to resolve the case. The public-safety payoff for all this effort is meager at best: According to a 2012 Human Rights Watch report that tracked 30,000 New Yorkers with no prior convictions when they were arrested for marijuana possession, 90 percent had no subsequent felony convictions. Only 3.1 percent committed a violent offense."
Jesse Wegman, The Injustice of Marijuana Arrests, New York Times, July 28, 2014.