Marijuana

A marijuana plant is seen growing at Med Grow Cannabis College in Southfield, Mich., Tuesday, Dec. 14, 2010. Michigan's two-year-old law allowing the use of marijuana for medical purposes is leaving communities, courts, patients and police locked in disputes over what is legal and what isn’t. (AP Photo/Carlos Osorio)

Marijuana

A marijuana plant is seen growing at Med Grow Cannabis College in Southfield, Mich., Tuesday, Dec. 14, 2010. Michigan's two-year-old law allowing the use of marijuana for medical purposes is leaving communities, courts, patients and police locked in disputes over what is legal and what isn’t. (AP Photo/Carlos Osorio)

Marijuana

A marijuana plant is seen growing at Med Grow Cannabis College in Southfield, Mich., Tuesday, Dec. 14, 2010. Michigan's two-year-old law allowing the use of marijuana for medical purposes is leaving communities, courts, patients and police locked in disputes over what is legal and what isn’t. (AP Photo/Carlos Osorio)

Medical Marijuana

FILE - This July 1, 2011 file photo shows fake marijuana displayed in a case, at The 2811 Club, a private cannabis club that plans to dispense marijuana to medically qualified patients in Phoenix.  (AP Photo/Ross D. Franklin, File)

Medical Marijuana

FILE - This July 1, 2011 file photo shows fake marijuana displayed in a case, at The 2811 Club, a private cannabis club that plans to dispense marijuana to medically qualified patients in Phoenix.  (AP Photo/Ross D. Franklin, File)

Medical Marijuana

 (AP Photo/Ross D. Franklin, File)

Medical marijuana

While holding up their medical marijuana cards, Dennis Cox, left, and Mike Gonzalez, right, wait as the first two people in line prior to the opening at Arizona Organix, the first legal medical marijuana dispensary to open in Arizona, Thursday Dec. 6, 2012, in Glendale, Ariz. Several dozen waited outside for the Glendale dispensary to open, the first among 96 applicants chosen through a lottery system for 126 geographic areas across the state.(AP Photo/Ross D. Franklin)

Medical marijuana

Medical Marijuana

Marijuana club

Allan Sobol, one of the owners of the 2811 Club, converses with a security guard outside the shop in a Phoenix strip mall. Sobol believes a provision in the medical marijuana law approved by voters allows these clubs, where members can obtain free drugs, to spring up all over the state. (Capitol Media Services photo by Howard Fischer)

Marijuana clubs

Someone could get a 3-gram vial of this ``blueberry silver'' strain of marijuana for free -- if the person is a dues-paying member of the 2811 Club. State Health Director Will Humble is questioning whether the operation violates the state's medical marijuana laws. (Capitol Media Services photo by Howard Fischer)

Marijuana clubs

Mike Miller of the Arizona Compassion Association, which gives away free marijuana, presides over his counter in a corner of the 2811 Club. Dues-paying members of the club can get free samples, in medicine bottles on the shelf. (Capitol Media Services photo by Howard Fischer)

Marijuana clubs

Mike Miller of the Arizona Compassion Association, which gives away free marijuana, presides over his counter in a corner of the 2811 Club. Dues-paying members of the club can get free samples, in medicine bottles on the shelf. (Capitol Media Services photo by Howard Fischer)

Marijuana clubs

Someone could get a 3-gram vial of this ``blueberry silver'' strain of marijuana for free -- if the person is a dues-paying member of the 2811 Club. State Health Director Will Humble is questioning whether the operation violates the state's medical marijuana laws. (Capitol Media Services photo by Howard Fischer)

Marijuana club

Allan Sobol, one of the owners of the 2811 Club, converses with a security guard outside the shop in a Phoenix strip mall. Sobol believes a provision in the medical marijuana law approved by voters allows these clubs, where members can obtain free drugs, to spring up all over the state. (Capitol Media Services photo by Howard Fischer)

Marijuana clubs

Mike Miller of the Arizona Compassion Association, which gives away free marijuana, presides over his counter in a corner of the 2811 Club. Dues-paying members of the club can get free samples, in medicine bottles on the shelf. (Capitol Media Services photo by Howard Fischer)

Marijuana clubs

Mike Miller of the Arizona Compassion Association, which gives away free marijuana, presides over his counter in a corner of the 2811 Club. Dues-paying members of the club can get free samples, in medicine bottles on the shelf. (Capitol Media Services photo by Howard Fischer)

Marijuana clubs

Mike Miller of the Arizona Compassion Association, which gives away free marijuana, presides over his counter in a corner of the 2811 Club. Dues-paying members of the club can get free samples, in medicine bottles on the shelf. (Capitol Media Services photo by Howard Fischer)

Marijuana clubs

Mike Miller of the Arizona Compassion Association, which gives away free marijuana, presides over his counter in a corner of the 2811 Club. Dues-paying members of the club can get free samples, in medicine bottles on the shelf. (Capitol Media Services photo by Howard Fischer)

Marijuana clubs

Someone could get a 3-gram vial of this ``blueberry silver'' strain of marijuana for free -- if the person is a dues-paying member of the 2811 Club. State Health Director Will Humble is questioning whether the operation violates the state's medical marijuana laws. (Capitol Media Services photo by Howard Fischer)

Marijuana club

Allan Sobol, one of the owners of the 2811 Club, converses with a security guard outside the shop in a Phoenix strip mall. Sobol believes a provision in the medical marijuana law approved by voters allows these clubs, where members can obtain free drugs, to spring up all over the state. (Capitol Media Services photo by Howard Fischer)

Medical marijuana

Medical marijuana