The ruling by the 9th U.S. Circuit Court of Appeals in San Francisco came in a lawsuit filed by S. Rowan Wilson, a Nevada woman who said she tried to buy a firearm for self-defense in 2011 after having obtained a medical marijuana card. The gun store refused, citing the federal rule banning the sale of firearms to illegal drug users.

Marijuana remains illegal under federal law, and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives has told gun sellers they can assume that a person with a medical marijuana card uses the drug. [Read more at NBC News]