LOS ANGELES (CBS) — The city of Los Angeles has been considering a ban on all pot shops, but it wouldn’t be needed in the north San Fernando Valley, where police have essentially enforced a ban of their own.

The LAPD shut down the last marijuana dispensary in the north San Fernando Valley, one of the last among shops in Northridge, Granada Hills and Chatsworth, as part of a three-year crackdown, the Los Angeles Daily News reported. Three owners of Herbal Medicine Care in Chatsworth were arrested on suspicion of felony possession of marijuana for sale.

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The dispensaries are required by state law to be non-profits, where collective members all contribute to the growing and harvesting of the drug, but police say shops simply sign people up and are instantly given collective membership, where the marijuana is handed out for a “predetermined donation,” LAPD Detective Robert Holcomb told the Daily News.

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The ban proposed by Councilman Jose Huizar would require all dispensaries to be shut down on the basis that even those permitted by the city are in violation of federal law because marijuana is considered an illegal drug.

Dispensaries with storefronts would be outlawed and those who need the drug would need to grow it at home, according to Huizar.

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An estimated 200 dispensaries remain open in the Valley.