A spokeswoman for the DEA told the Los Angeles Times that the letters were intended to "educate" property owners that they could face federal prosecution for housing medical marijuana dispensaries. It is estimated that approximately 180 dispensaries are operating in the Los Angeles area.

"This letter shall serve as notice that, after a thorough investigation, the DEA has determined there is a marijuana dispensary operating on the above described property," the letter states. "Federal law allows for the seizure of assets, including real property, which have been used in conjunction with the distribution of controlled substances. … It is not a defense to this crime or to the seizure of the property that the facility operating on the property is providing ‘medical marijuana’ under California law including the provisions of California Prop. 215. Violation of this law is a felony crime, and carries with it a penalty of up to 20 years in prison."

California NORML Coordinator Dale Gieringer called the DEA’s threat a "a serious attack on patients' access to medical marijuana under California law," and noted that the letters were mailed just days before the federal House of Representatives is scheduled to vote on an amendment limiting the US Justice Department’s ability to federally prosecute patients and caregivers who are compliant with state medical marijuana laws.