Black Market Sales Continue to Cast a Shadow Over the State's Pot Experiment. L.A. County is Exhibit A.

Six months after cannabis sales became legal, marijuana’s black market continues to be a thorn in California’s side. Unlicensed and unregulated pot shops still flourish, draining the legal market of customers and contributing to the state’s underwhelming tax revenues.

The problem is especially acute in Los Angeles County. Officials don’t have an exact figure, but they believe the number of illegal shops far outweighs the county’s 150 legitimate businesses. Many customers don’t even know the shops they frequent are illegal.

State and local regulators have been cracking down. But, as the New York Times notes, even when they catch the culprits, there’s only so much they can do.

…the voter-approved ballot measure legalizing cannabis in California included a provision that made possessing more than 28.5 grams only a misdemeanor. That means officers can seize businesses' cash and marijuana, but employees and owners rarely face jail, and illegal operations often quickly reopen.

"It's a money-lucrative business so there are people willing to take the risk," said Capt. Holly Francisco, who commands the sheriff's department's narcotics unit.

In Lake County, where some of the weed originates, authorities are also struggling to keep up with the illicit trade.

"It's all about manpower," Sheriff Brian Martin said. "No one has enough of it."