Outside New York City Hall, a policeman watches a protest against racial disparities in marijuana arrests. The majority of those arrested are black or Latino, even though those groups are not more likely to smoke pot.
Andrew Burton/Getty Images
Partygoers listen to live music and smoke pot on the second of two days at the annual 4/20 marijuana festival in Denver, last month. While the sale of marijuana is legal in the state, a legal finance mechanism is still in doubt.
The legalization of marijuana could dry up a revenue stream for police, according to reports. Here, two men share a water pipe underneath the Space Needle shortly after a law legalizing the recreational use of marijuana took effect in Seattle in 2012.
Stephen Brashear/Getty Images
A man uses the Nasal Ranger to detect smells in the southern U.S., in this photo provided by St. Croix Sensory. In Denver, the device is being used to monitor complaints of strong marijuana smells.
Courtesy of Nasal Ranger
An ATM sits next to a rack of marijuana clone plants that are used to grow medical marijuana on Wednesday at The Joint, a medical marijuana cooperative in Seattle. Last week Washington became the second U.S. state to adopt rules for the recreational sale of marijuana.
Ted S. Warren/AP
A man smokes marijuana outside Uruguay's parliament in Montevideo on Wednesday, where lawmakers in the lower house debated and passed a bill that would legalize marijuana and regulate its production and distribution.