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 hide caption

itoggle caption Courtesy of Nasal Ranger

An aerial image shows the Gold Star cargo ship ablaze. Officials say the ship's crew set fire to 30 tons of hashish after authorities approached the vessel for inspection. Guardia di Finanza hide caption

itoggle caption Guardia di Finanza

Sen. Patrick Leahy is calling on the Justice Department to state its position on marijuana's legal status. Here, a man inspects a shirt depicting the U.S. flag made of marijuana symbols, at a medical marijuana show in Los Angeles earlier this year. Robyn Beck/AFP/Getty Images hide caption

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Young backers of a bill to legalize the production and trade of marijuana in Uruguay wait outside the Parliament building as lawmakers debate the bill Wednesday. AFP/Getty Images hide caption

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A photograph taken on May 20, 2013, by the DEA Strike Force shows some of the marijuana plants the agency says were grown by a woman from a wealthy New York suburb, in a warehouse in the Queens borough of New York. DEA/AP hide caption

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Marijuana gingerbread cookies, like this one sold at The Apothecarium in San Francisco, could easily appeal to kids. Jeff Chiu/AP hide caption

itoggle caption Jeff Chiu/AP

William von Schneidau, who owns the BB Ranch butcher shop at Pike Place Market in Seattle, has made prosciutto from pigs fed marijuana. Courtesy of BB Ranch hide caption

itoggle caption Courtesy of BB Ranch

Colorado lawmakers approved two taxes on marijuana — a 15 percent excise tax, and a 10 percent sales tax. A photo depicts a quarter of an ounce, left, and one ounce of marijuana, along with a handful of rolled joints at a Denver dispensary. Ed Andrieski/AP hide caption

itoggle caption Ed Andrieski/AP

A customer rolls a joint made of half marijuana and half tobacco in Olympia, Wash., on December 9, 2012. Nick Adams/Reuters/Landov hide caption

itoggle caption Nick Adams/Reuters/Landov

People at a Denver party early this month celebrate the recognition of an amendment to the Colorado constitution legalizing recreational use of marijuana. Brennan Linsley/AP hide caption

itoggle caption Brennan Linsley/AP

A woman, identified only as "Hurricane," lights up in Seattle. Washington state's law legalizing the recreational use of marijuana went into effect on Dec. 6. Cliff Despeaux /Reuters /Landov hide caption

itoggle caption Cliff Despeaux /Reuters /Landov