Marijuana

With marijuana on the ballot in four U.S. states this November, most prominently California's Proposition 19, which would fully legalize the substance, the legalization of marijuana has become a hot topic of discussion in North America. If pot were to become legal in California, it is unclear how that would affect the ongoing drug wars in neighboring Mexico - whether it would increase, decrease, or have little effect on the widespread violence. What is clear is that U.S. Attorney General Eric Holder has declared that the federal Justice Department will continue to prosecute those who use or distribute recreational marijuana, regardless of any change to state law. Collected here are photos from the past year of marijuana in the news, for both medicinal and recreational purposes, and some of the legal entanglements involved.

1. Tim Blakeley, manager of Sunset Junction medical marijuana dispensary, shows marijuana plant buds on May 11, 2010 in Los Angeles, California. The dispensary was one 25 plaintiffs in a lawsuit against the city of Los Angeles that fought to stay open after city prosecutors notified 439 medical marijuana dispensaries that they had to shut down by June 7, 2010. (Kevork Djansezian/Getty Images)

2. Gardener Eli Rodriguez, a new Teamsters member, removes dead matter and cleans up marijuana plants at Marjyn Investments, a marijuana growing operation in Oakland, California on Monday, Sept. 20, 2010. The Teamsters added nearly 40 new members earlier this month by organizing the country's first group of unionized marijuana growers. (AP Photo/Eric Risberg)

3. A marijuana user rolls a joint during a 420 Day celebration on "Hippie Hill" in Golden Gate Park April 20, 2010 in San Francisco, California. April 20th has become a de facto holiday for marijuana advocates, with large gatherings and "smoke outs" in many parts of the United States. (Justin Sullivan/Getty Images)

4. An unidentified man smokes marijuana at a demonstration in favor of legalizing marijuana in Mexico City, Mexico on Sunday Sept. 5, 2010. (AP Photo/Marco Ugarte)

5. An estimated 12,000 to 15,000 people all exhale marijuana smoke as the clock hit 4:20pm during a 420 event on Norlin Quad at the University of Colorado in Boulder, Colorado April 20, 2010. (REUTERS/Mark Leffingwell)

6. A medical-marijuana user holds a homegrown bud in Portland, Maine on Oct. 22, 2009. On Friday, July 9, 2010, the winning applications for Maine's medical marijuana dispensaries were announced by the Maine Department of Health and Human Services. (AP Photo/Robert F. Bukaty)

7. Marijuana salesperson Marissa Dodd (left) bags up a sale for a customer at Dr. Reefer's marijuana dispensary April 20, 2010 at the University of Colorado in Boulder, Colorado. Colorado, one of 14 states to allow use of medical marijuana, has experienced an explosion in marijuana dispensaries, trade shows and related businesses in the last year as marijuana use becomes more mainstream here. (Chris Hondros/Getty Images)

8. A client enters Sunset Junction medical marijuana dispensary on May 11, 2010 in Los Angeles, California. (Kevork Djansezian/Getty Images)

9. Billings Police and Fire Departments investigate the scene of a firebomb that was thrown through the front door of Montana Therapeutics, a medical marijuana store early on Monday, May 10, 2010 in Billings, Montana. The fire was quickly put out and Billings police were investigating. On September 28th, 2010, the Billings City Council voted to extend for a year its moratorium on any new medical marijuana businesses. The city has issued more than 80 existing business licenses for the stores. (AP Photo/Billings Gazette, Billings Gazette)

10. A man is arrested by Aspen police in the lobby of the hotel holding the Cannabis Crown 2010 expo April 18, 2010 in Aspen, Colorado. The man was detained by hotel security after carrying a large jar of marijuana out of the marijuana trade show in the basement event space downstairs. Aspen police then found the man has no medical marijuana license and was also carrying a set of brass knuckles, which are illegal in Colorado. The marijuana he carried was confiscated and destroyed, according to police. (Chris Hondros/Getty Images)

11. A soldier pulls marijuana plants up in an illegal plantation at the Sierra de Juarez, in Tecate, northern Mexico on Tuesday, Sept. 21, 2010. Authorities found three illegal plantations of marijuana on Sept. 20 during air patrol operations. (AP Photo/Guillermo Arias)

12. A soldier stands over an altar in a camp used by marijuana growers during a marijuana destruction operation in the Sierra de Juarez in Ensenada, Mexico on Thursday Sept. 30, 2010. According to Army Gen. Alfonso Duarte Mujica, soldiers destroyed 180 acres of marijuana in the northern region of Mexico's Baja California peninsula in 2010. (AP Photo/Guillermo Arias)

13. Police are pictured with two of the 14 wild black bears that were guarding an illegal marijuana growing operation after a July 30, 2010 raid on the property in the Christina Lake area in southeastern British Columbia. Police told AFP the bears were fed dog food to keep them nearby to deter drug thieves. But feeding wildlife is illegal in Canada, and following the raid authorities said the bears might be killed because they could become dangerous when the feeding ended. That threat prompted thousands of people around the world to sign petitions, and join a Facebook group, to save the bears. Authorities in British Columbia ordered a reprieve on August 31, 2010 for some two dozen bears caught in a drug bust. (AFP/Getty Images)

14. A Mexican soldier arranges blocks of marijuana, weighing a total of 46 tons, before they are incinerated at a military base in the border city of Tijuana May 11, 2010. (REUTERS/Jorge Duenes)

15. A soldier walks through a cloud of smoke from burning marijuana on an illegal plantation at the Sierra de Juarez, in Tecate, northern Mexico, Tuesday, Sept. 21, 2010. (AP Photo/Guillermo Arias)

16. The slain body of a drug hitman is seen among branches after an operation by Mexican soldiers at a ranch near the municipality of Sabinas Hidalgo, some 100 km away from Monterrey, Mexico on April 27, 2010. The army freed sixteen people, including a woman and her son during an operation at a ranch used by hitmen as a safe house, according to local media. The army also seized machine guns, ammunition, four trucks and some 2 tons of marijuana. Two gunmen died during the operation. (REUTERS/Tomas Bravo)

17. A baby boy without a name, either abandoned or rescued from domestic or drug violence, rests in a crib at the Ciudad Juarez branch of Mexico's DIF family development agency August 16, 2010. Neither Mexico's government nor the various independent groups studying organized crime keep track of the number of children dubbed "narco orphans," who have lost one or both parents to the drug war, yet with poor education already holding back Mexico's youth, social workers worry about the impact on society of tens of thousands of kids growing up emotionally traumatized. The sign on the crib reads "Male without name, (surname) Solis." (REUTERS/Claudia Daut)

18. Mexican soldiers stand in formation as 46 tons of marijuana is incinerated at a military base in the border city of Tijuana May 11, 2010. (REUTERS/Jorge Duenes)

19. U.S. Marine Cpl. Jake Hoag of Bend, Oregon from India Battery, 3rd Battalion, 12th Marine Regiment questions a marijuana farmer while on patrol near Forward Operating Base (FOB) Zeebrugge on October 10, 2010 near Kajaki, Afghanistan. (Scott Olson/Getty Images)

20. Len Goodman poses among his marijuana plants near Santa Fe, New Mexico on Thursday, July 15, 2010. He is one of just 11 growers approved by New Mexico to produce pot for all of the state's 2,000 registered medical marijuana patients, and his customers routinely exhaust his supply. (AP Photo/Susan Montoya Bryan)

21. Drew Brown, a vice president at Abundant Healing store (left), hands over a check to one of his marijuana suppliers on April 19, 2010 in Fort Collins, Colorado. Abundant Healing is one of Colorado's many legal marijuana dispensaries, which sells marijuana to customers with a state-issued medical marijuana card. (Chris Hondros/Getty Images)

22. Douglas Hiatt throws up his arms as he talks about a signature campaign for an initiative to legalize marijuana for adults falling short Thursday, July 1, 2010, in Seattle, Washington. Hiatt, one of the campaign's leaders, said that the effort to get Initiative 1068 on the ballot has fallen short by about 40,000-50,000 signatures of about 241,000 required. Initiative 1068 would have removed all state penalties for marijuana possession, cultivation, use and sale. (AP Photo/Elaine Thompson)

23. A police officer stands guard during a drug destruction in Panama City, Friday, Oct. 8, 2010. According to officials, some 4.7 tons of cocaine, marijuana and heroin seized by the police in different nationwide operations during the last month, were incinerated. (AP Photo/Arnulfo Franco)

24. A man smokes marijuana from a pipe during the International Day for the Legalization of Marijuana in Medellin, Antioquia Department, Colombia on May 8, 2010. (RAUL ARBOLEDA/AFP/Getty Images)(Photo Credit should Read /AFP/Getty Images)

25. Medical marijuana plants are pictured as they dry in the Los Angeles area on June 1, 2010. Some 440 medical marijuana dispensaries across Los Angeles were under orders to close on June 7, 2010, nearly five months after city officials, worried that the shops were mushrooming out of control, voted to shut most of them down. (REUTERS/Mario Anzuoni)

26. Dani Geen holds up 1.5 gram "care packages" of medical marijuana at the Harborside Health Center in Oakland, California on Aug. 3, 2010, where, until recently, the center had a program that gave out free weekly "care packages" to about 600 patients on unemployment or pensions. (AP Photo/Ben Margot)

27. Marijuana is harvested in Davenport, California on Tuesday, Oct. 12, 2010. (AP Photo/Marcio Jose Sanchez)

28. Nicholas Pouch uses a glass pipe to smoke medical marijuana Friday, May 21, 2010, in his glass-blowing shop in Matlock, Washington. Pouch's use of marijuana is legal under state laws, but it has been a factor in his ongoing child-custody battle with the mother of his two sons. (AP Photo/Ted S. Warren)

29. Tim Blakeley, manager of Sunset Junction medical marijuana dispensary, shows a marijuana plant bud under a magnifying glass, reflecting the dispensary's overhead lights, on May 11, 2010 in Los Angeles, California. (Kevork Djansezian/Getty Images)

30. Crystal Guess speaks during a news conference to launch the Women's Marijuana Movement in the State Capitol in downtown Denver, Colorado on May 6, 2010. Moms got tougher drunk-driving laws on the books and were directly responsible for passing and then repealing alcohol Prohibition. Now marijuana activists are trying to enlist the nation's mothers in legalization efforts with a sales pitch that pot is safer than booze. (AP Photo/David Zalubowski)

31. Lindsey Bradshaw, who is missing his spleen and kidney and part of his stomach, colon and pancreas uses a number of methods to help with pain, including medical marijuana, in Portland, Oregon. Graham, who takes his food through the tube attached to the bag at left, says most of his days are spent inside his home in southeast Portland where he can quickly access his painkillers and keep tabs on his health. Photo taken on July 21, 2010. (AP Photo/The Oregonian, Jamie Francis)

32. Marijuana plants lay in a pile before being burned by the army in the Sierra de Juarez in Ensenada, Mexico on Thursday Sept. 30, 2010. (AP Photo/Guillermo Arias)