An employee checks cannabis plants at a medical marijuana plantation in northern Israel March 21, 2017. Picture taken March 21, 2017. REUTERS/Nir Elias

Young cannabis plants are seen at a medical marijuana plantation in northern Israel March 21, 2017. Picture taken March 21, 2017. REUTERS/Nir Elias

An employee prepares medical marijuana joints at a plantation in northern Israel March 21, 2017. Picture taken March 21, 2017. REUTERS/Nir Elias

An employee sweeps bits of harvested cannabis on the floor at a medical marijuana plantation in northern Israel March 21, 2017. Picture taken March 21, 2017. REUTERS/Nir Elias

A customer rolls a joint with cannabis bought at Dr Green shop in Lausanne, Switzerland March 17, 2017. REUTERS/Denis Balibouse

Anti-narcotics workers tests marihuana during an incineration of about 7.9 tons of drugs, seized during police operations, according to the Interior Ministry, in Lima, Peru February 2, 2017. REUTERS/Guadalupe Pardo

An unnamed worker waters cannabis plants on Steve Dillon's farm in Humboldt County, California, U.S. August 28, 2016. REUTERS/Rory Carroll/File Photo

A variety of medicinal marijuana buds in jars are pictured at Los Angeles Patients & Caregivers Group dispensary in West Hollywood, California U.S., October 18, 2016. REUTERS/Mario Anzuoni/File Photo

A variety of medicinal marijuana buds in jars are pictured at Los Angeles Patients & Caregivers Group dispensary in West Hollywood, California U.S., October 18, 2016. Picture taken October 18, 2016. REUTERS/Mario Anzuoni/File Photo

Clones of medicinal marijuana plants are pictured at Los Angeles Patients & Caregivers Group dispensary in West Hollywood, California U.S., October 18, 2016. Picture taken October 18, 2016. REUTERS/Mario Anzuoni/File Photo

UPDATE Update Mapa de Estados Unidos que señala los estados que permiten el uso recreativo y medicinal de la marihuana. 22 cm de ancho.(SGN02)

Medical marijuana is displayed in Los Angeles, California, U.S. August 6, 2007. REUTERS/Mario Anzuoni/File Photo

Chef Christopher Sayegh holds some marijuana buds and THC (Tetrahydrocannabinol) and CBD (Cannabidiol) oils as he poses in his kitchen in Los Angeles, U.S., April 29, 2016. REUTERS/Mario Anzuoni

Marijuana buds are pictured in chef Christopher Sayegh's kitchen in Los Angeles, U.S., April 29, 2016. REUTERS/Mario Anzuoni

Chef Chris Sayegh holds marijuana buds and THC (Tetrahydrocannabinol) and CBD (Cannabidiol) oils as he poses in his kitchen in Los Angeles, U.S., April 29, 2016. REUTERS/Mario Anzuoni

Thousands of marijuana enthusiasts gather on "Hippie Hill" in San Francisco's Golden Gate Park to light up joints, pipes and bongs in celebration of the annual but informal cannabis holiday, named 4/20 in San Francisco, California April 20, 2016. REUTERS/Curtis Skinner

Thousands of marijuana enthusiasts gather on "Hippie Hill" in San Francisco's Golden Gate Park to light up joints, pipes and bongs in celebration of the annual but informal cannabis holiday, named 4/20 in San Francisco, California April 20, 2016. REUTERS/Curtis Skinner

A worker tends to cannabis plants at a plantation near the northern Israeli city of Safed, in this June 11, 2012 file picture. REUTERS/Baz Ratner/Files TPX IMAGES OF THE DAY

A Hindu holy man, or sadhu, prepares marijuana before smoking it during the Shivaratri festival on the premises of Pashupatinath Temple in Kathmandu, Nepal, March 7, 2016. Hindu holy men from Nepal and India come to this temple to take part in the Maha Shivaratri festival. Celebrated by Hindu devotees all over the world, Shivaratri is dedicated to Lord Shiva, and holy men mark the occasion by praying, smoking marijuana or smearing their bodies with ashes. REUTERS/Navesh Chitrakar

A Hindu holy man, or sadhu, smokes marijuana in a chillum during the Shivaratri festival on the premises of Pashupatinath Temple in Kathmandu, Nepal, March 7, 2016. Hindu holy men from Nepal and India come to this temple to take part in the Maha Shivaratri festival. Celebrated by Hindu devotees all over the world, Shivaratri is dedicated to Lord Shiva, and holy men mark the occasion by praying, smoking marijuana or smearing their bodies with ashes. REUTERS/Navesh Chitrakar

A Hindu holy man, or sadhu, smeared with ashes holds a chillum as he smokes it during the Shivaratri festival on the premises of Pashupatinath Temple in Kathmandu, Nepal, March 7, 2016. Hindu holy men from Nepal and India come to this temple to take part in the Maha Shivaratri festival. Celebrated by Hindu devotees all over the world, Shivaratri is dedicated to Lord Shiva, and holy men mark the occasion by praying, smoking marijuana or smearing their bodies with ashes. REUTERS/Navesh Chitrakar

A plate filled with marijuana is kept for sale during the Shivaratri festival at the premises of Pashupatinath Temple in Kathmandu, Nepal, March 7, 2016. Hindu holy men from Nepal and India come to this temple to take part in the Maha Shivaratri festival. Celebrated by Hindu devotees all over the world, Shivaratri is dedicated to Lord Shiva, and holy men mark the occasion by praying, smoking marijuana or smearing their bodies with ashes. REUTERS/Navesh Chitrakar

A Hindu holy man, or sadhu, smeared with ashes smokes marijuana in a chillum during the Shivaratri festival on the premises of Pashupatinath Temple in Kathmandu, Nepal, March 7, 2016. Hindu holy men from Nepal and India come to this temple to take part in the Maha Shivaratri festival. Celebrated by Hindu devotees all over the world, Shivaratri is dedicated to Lord Shiva, and holy men mark the occasion by praying, smoking marijuana or smearing their bodies with ashes. REUTERS/Navesh Chitrakar TPX IMAGES OF THE DAY

A Hindu holy man, or sadhu, smokes marijuana in a chillum on the premises of Pashupatinath Temple in Kathmandu, Nepal March 6, 2016. Hindu holy men from Nepal and India come to this temple to take part in the Maha Shivaratri festival. Celebrated by Hindu devotees all over the world, Shivaratri is dedicated to Lord Shiva, and holy men mark the occasion by praying, smoking marijuana or smearing their bodies with ashes. REUTERS/Navesh Chitrakar

A Hindu holy man, or sadhu, smokes marijuana in a chillum on the premises of Pashupatinath Temple in Kathmandu, Nepal March 6, 2016. Hindu holy men from Nepal and India come to this temple to take part in the Maha Shivaratri festival. Celebrated by Hindu devotees all over the world, Shivaratri is dedicated to Lord Shiva, and holy men mark the occasion by praying, smoking marijuana or smearing their bodies with ashes. REUTERS/Navesh Chitrakar

The inside of the Columbia Care medical marijuana dispensary is seen in New York January 7, 2016. New York's first medical marijuana dispensaries are opening their doors on Thursday, as the state launches one of the most conservative programs of its kind in the United States. REUTERS/Shannon Stapleton

The logo for the Columbia Care marijuana dispensary is seen though a window outside the clinic in New York January 7, 2016. New York's first medical marijuana dispensaries are opening their doors on Thursday, as the state launches one of the most conservative programs of its kind in the United States. REUTERS/Shannon Stapleton

The logo for the Columbia Care marijuana dispensary is seen though a window outside the clinic in New York January 7, 2016. New York's first medical marijuana dispensaries are opening their doors on Thursday, as the state launches one of the most conservative programs of its kind in the United States. REUTERS/Shannon Stapleton

An iPad is seen inside the Columbia Care marijuana dispensary in New York January 7, 2016. New York's first medical marijuana dispensaries are opening their doors on Thursday, as the state launches one of the most conservative programs of its kind in the United States. REUTERS/Shannon Stapleton

Nicholas Vita, the chief executive of Columbia Care marijuana dispensary, poses inside the clinic in New York January 7, 2016. New York's first medical marijuana dispensaries are opening their doors on Thursday, as the state launches one of the most conservative programs of its kind in the United States. REUTERS/Shannon Stapleton

A pamphlet is seen inside the Columbia Care medical marijuana dispensary in New York January 7, 2016. New York's first medical marijuana dispensaries are opening their doors on Thursday, as the state launches one of the most conservative programs of its kind in the United States. REUTERS/Shannon Stapleton

A 29-year old women (R) and her 13-year-old relative (who asked to withhold their names) work sifting cannabis inside a garage in the Bekaa valley, Lebanon November 1, 2015. The woman fled Raqqa two months before with her 5-year-old son; her husband and other son are still in Raqqa. She works harvesting many crops, including cannabis, to support her family and is hoping to bring them to Lebanon. REUTERS/Alia Haju PICTURE 13 OF 18 - SEARCH "HAJU HASHISH" FOR ALL IMAGES

A man smokes a joint as he holds a banner reading "Legalize it" during a 420 dance party to demand legalisation and to celebrate marijuana culture outside the Senate building in Mexico City, in this May 3, 2014 file photo. The legalization of marijuana is "irreversible" in drug-scarred Mexico following a key court ruling, former President Vicente Fox says, forecasting all drugs including cocaine and crystal meth will be freely available within a decade. Earlier this month, the Supreme Court gave the green light to growing marijuana for recreational use, a landmark decision that blasts open the door for an eventual legalization in Mexico, where warring gangs sparked a decade of drug violence. REUTERS/Tomas Bravo/Files TPX IMAGES OF THE DAY

Supreme Court judge Arturo Zaldivar Lelo de Larrea attends a meeting at Supreme Court building in Mexico City, Mexico, November 4, 2015. Mexico's Supreme Court on Wednesday gave the green light to growing marijuana for recreational use in a landmark decision that could lead to legalization in a country with a bloody history of conflict with drug cartels. Ruling on a case first brought in 2013 by an advocacy group denied permission by regulators to grow plants for recreational use, the court set a precedent by voting 4-1 that prohibiting people from growing the drug to consume it was unconstitutional. The court's vote does not legalize marijuana consumption in Mexico, but more rulings of the same kind could set a legal precedent. REUTERS/Edgard Garrido

A man gestures during a demonstration in support of the legalization of marijuana outside the Supreme Court building in Mexico City, Mexico, November 4, 2015. Mexico's Supreme Court on Wednesday gave the green light to growing marijuana for recreational use in a landmark decision that could lead to legalization in a country with a bloody history of conflict with drug cartels. Ruling on a case first brought in 2013 by an advocacy group denied permission by regulators to grow plants for recreational use, the court set a precedent by voting 4-1 that prohibiting people from growing the drug to consume it was unconstitutional. The court's vote does not legalize marijuana consumption in Mexico, but more rulings of the same kind could set a legal precedent. REUTERS/Edgard Garrido

A man gestures during a demonstration in support of the legalization of marijuana outside the Supreme Court building in Mexico City, Mexico, November 4, 2015. Mexico's Supreme Court on Wednesday gave the green light to growing marijuana for recreational use in a landmark decision that could lead to legalization in a country with a bloody history of conflict with drug cartels.Ruling on a case first brought in 2013 by an advocacy group denied permission by regulators to grow plants for recreational use, the court set a precedent by voting 4-1 that prohibiting people from growing the drug to consume it was unconstitutional.The court's vote does not legalize marijuana consumption in Mexico, but more rulings of the same kind could set a legal precedent. REUTERS/Edgard Garrido

A woman smokes as she smiles during a demonstration in support of the legalization of marijuana outside the Supreme Court building in Mexico City, Mexico, November 4, 2015. Mexico's Supreme Court on Wednesday gave the green light to growing marijuana for recreational use in a landmark decision that could lead to legalization in a country with a bloody history of conflict with drug cartels.Ruling on a case first brought in 2013 by an advocacy group denied permission by regulators to grow plants for recreational use, the court set a precedent by voting 4-1 that prohibiting people from growing the drug to consume it was unconstitutional.The court's vote does not legalize marijuana consumption in Mexico, but more rulings of the same kind could set a legal precedent. REUTERS/Edgard Garrido

Supreme Court judge Arturo Zaldivar Lelo de Larrea attends a meeting at Supreme Court building in Mexico City, Mexico, November 4, 2015. Mexico's Supreme Court on Wednesday gave the green light to growing marijuana for recreational use in a landmark decision that could lead to legalization in a country with a bloody history of conflict with drug cartels.Ruling on a case first brought in 2013 by an advocacy group denied permission by regulators to grow plants for recreational use, the court set a precedent by voting 4-1 that prohibiting people from growing the drug to consume it was unconstitutional.The court's vote does not legalize marijuana consumption in Mexico, but more rulings of the same kind could set a legal precedent. REUTERS/Edgard Garrido

A man gestures during a demonstration in support of the legalization of marijuana outside the Supreme Court building in Mexico City, Mexico, November 4, 2015. Mexico's Supreme Court on Wednesday gave the green light to growing marijuana for recreational use in a landmark decision that could lead to legalization in a country with a bloody history of conflict with drug cartels.Ruling on a case first brought in 2013 by an advocacy group denied permission by regulators to grow plants for recreational use, the court set a precedent by voting 4-1 that prohibiting people from growing the drug to consume it was unconstitutional.The court's vote does not legalize marijuana consumption in Mexico, but more rulings of the same kind could set a legal precedent. REUTERS/Edgard Garrido

Men hold signs during a demonstration in support of the legalization of marijuana outside the Supreme Court building in Mexico City, Mexico, November 4, 2015. Mexico's Supreme Court on Wednesday gave the green light to growing marijuana for recreational use in a landmark decision that could lead to legalization in a country with a bloody history of conflict with drug cartels.Ruling on a case first brought in 2013 by an advocacy group denied permission by regulators to grow plants for recreational use, the court set a precedent by voting 4-1 that prohibiting people from growing the drug to consume it was unconstitutional.The court's vote does not legalize marijuana consumption in Mexico, but more rulings of the same kind could set a legal precedent. The signs read, "#Self-cultivation yes, #Cannabis uncensored". REUTERS/Edgard Garrido

A man holds a sign during a demonstration in support of the legalization of marijuana outside the Supreme Court building in Mexico City, Mexico, November 4, 2015. Mexico's Supreme Court on Wednesday gave the green light to growing marijuana for recreational use in a landmark decision that could lead to legalization in a country with a bloody history of conflict with drug cartels.Ruling on a case first brought in 2013 by an advocacy group denied permission by regulators to grow plants for recreational use, the court set a precedent by voting 4-1 that prohibiting people from growing the drug to consume it was unconstitutional.The court's vote does not legalize marijuana consumption in Mexico, but more rulings of the same kind could set a legal precedent. REUTERS/Edgard Garrido

Activist Ray Turmel holds a bag of medical marijuana while he smokes a marijuana cigarette, as he calls for the total legalization of marijuana, outside the building where the federal election Munk Debate on Canada’s Foreign Policy is being held in Toronto, Canada, September 28, 2015. REUTERS/Mark Blinch TPX IMAGES OF THE DAY TPX IMAGES OF THE DAY

A container of marijuana found during a search of a car by Cook County Sheriff police officers is seen as officers take a man into custody in the Austin neighborhood in Chicago, Illinois, United States, September 10, 2015. The focus on rounding up illegal guns, rather than low-level drug offenders, is an increasing priority for law enforcement in Chicago as murders - almost all of them with firearms and mostly related to gangs - have risen to 304 so far this year, compared with 258 in the same period last year. To match story USA-CRIME/CHICAGO-GUNS REUTERS/Jim Young

Soldiers stand guard as marijuana and other drugs are being incinerated at a camp of the Mexican Army's 28th infantry battalion in Tijuana, Mexico, August 18, 2015. A total of 138.7 tonnes of drugs seized during this administration, including 7 tonnes seized in Tijuana, were burned simultaneously in nine states across the country, in an incineration operation coordinated by Mexico's Attorney General office, local media reported. REUTERS/Jorge Duenes

Soldiers stand as marijuana and other drugs are being incinerated at a camp of the Mexican Army's 28th infantry battalion in Tijuana, Mexico, August 18, 2015. A total of 138.7 tonnes of drugs seized during this administration, including 7 tonnes seized in Tijuana, were burned simultaneously in nine states across the country, in an incineration operation coordinated by Mexico's Attorney General office, local media reported. REUTERS/Jorge Duenes

Soldiers march as marijuana and other drugs are being incinerated at a camp of the Mexican Army's 28th infantry battalion in Tijuana, Mexico, August 18, 2015. A total of 138.7 tonnes of drugs seized during this administration, including 7 tonnes seized in Tijuana, were burned simultaneously in nine states across the country, in an incineration operation coordinated by Mexico's Attorney General office, local media reported. REUTERS/Jorge Duenes

Soldiers are silhouetted as marijuana and other drugs are being incinerated at a camp of the Mexican Army's 28th infantry battalion in Tijuana, Mexico, August 18, 2015. A total of 138.7 tonnes of drugs seized during this administration, including 7 tonnes seized in Tijuana, were burned simultaneously in nine states across the country, in an incineration operation coordinated by Mexico's Attorney General office, local media reported. REUTERS/Jorge Duenes

A burning pile of marijuana and other drugs are being incinerated at a camp of the Mexican Army's 28th infantry battalion in Tijuana, Mexico, August 18, 2015. A total of 138.7 tonnes of drugs seized during this administration, including 7 tonnes seized in Tijuana, were burned simultaneously in nine states across the country, in an incineration operation coordinated by Mexico's Attorney General office, local media reported. REUTERS/Jorge Duenes TPX IMAGES OF THE DAY

Bird specialist Ronal Sibaja shows a cloth bag that was attached to the chest of a pigeon that was used to smuggle drugs into a prison at the Animal Rescue Zoo Ave in Alajuela August 18, 2015. Guards captured the bird in one of the patios of the La Reforma Penitentiary and found 14 grams of cocaine and 14 grams of marijuana in a little bag attached to its chest. Sibaja said that the pigeon cannot be released and will have to remain in captivity. REUTERS/Juan Carlos Ulate

The pigeon that was used to smuggle drugs into a prison is pictured in a cage at the Animal Rescue Zoo Ave in Alajuela August 18, 2015. Guards captured the bird in one of the patios of the La Reforma Penitentiary and found 14 grams of cocaine and 14 grams of marijuana in a little bag attached to its chest. Ronal Sibaja, a bird specialist at Zoo Ave, said that the pigeon cannot be released and will have to remain in captivity. REUTERS/Juan Carlos Ulate

The pigeon that was used to smuggle drugs into a prison is pictured in a cage at the Animal Rescue Zoo Ave in Alajuela August 18, 2015. Guards captured the bird in one of the patios of the La Reforma Penitentiary and found 14 grams of cocaine and 14 grams of marijuana in a little bag attached to its chest. Ronal Sibaja, a bird specialist at Zoo Ave, said that the pigeon cannot be released and will have to remain in captivity. REUTERS/Juan Carlos Ulate

The pigeon that was used to smuggle drugs into a prison is pictured in a cage at the Animal Rescue Zoo Ave in Alajuela August 18, 2015. Guards captured the bird in one of the patios of the La Reforma Penitentiary and found 14 grams of cocaine and 14 grams of marijuana in a little bag attached to its chest. Ronal Sibaja, a bird specialist at Zoo Ave, said that the pigeon cannot be released and will have to remain in captivity. REUTERS/Juan Carlos Ulate

Packets of synthetic marijuana illegally sold in New York City are put on display at a news conference held by New York state Senator Jeff Klein in New York, August 12, 2015. Illegal synthetic marijuana, or "weaponized" marijuana as police are calling it, is spreading across New York, particularly the city's homeless population in search of a cheap high but who often wind up hospitalized or dead, police say. REUTERS/Sebastien Malo

Vendors and marijuana enthusiasts gather at a "Weed the People" event to celebrate the legalization of recreational use of marijuana in Portland, Oregon July 3, 2015. Smoking marijuana became legal in Oregon on July 1, fulfilling the first step in a voter-approved initiative that will usher in a network of legal weed retail stores in 2016, similar to the systems already operating in neighboring Washington state and Colorado. REUTERS/Steve Dipaola

An officer shows a 1kg marijuana pack before burning it, next to a marijuana pile at a West Jakarta police office, June 15, 2015. Jakarta police burnt 581 kg of marijuana, and also destroyed more than 10,000 bottles of alcoholic drink, ahead of the holy month of Ramadan in Jakarta, local media reported. REUTERS/Beawiharta

A man smokes marijuana during a rally against drug trafficking and in favor for the legalization of self-cultivation of marijuana for medicinal and recreational purposes in Santiago, June 7, 2015. REUTERS/Ueslei Marcelino

People attend a rally in support of the decriminalisation of marijuana in Tbilisi, Georgia, June 2, 2015. REUTERS/David Mdzinarishvili

A man smokes marijuana during a demonstration in support of the legalization of marijuana in Sao Paulo May 23, 2015. REUTERS/Nacho Doce

A demonstrator smokes a marijuana cigarette during a protest outside the Capitol building in San Juan April 20, 2015. People gathered outside the Capitol building as legislators are debating to decriminalize small amounts of medical marihuana and its cultivation, according to local media. REUTERS/Alvin Baez

A Colombian police officer carries a pack of marijuana seized in Cali March 30, 2015. Colombian narcotics police seized 4.1 tons of marijuana from drug trafficking gangs in two houses in Corinto, Cauca, according to authorities. REUTERS/Jaime Saldarriaga