Medithrive, a cannabis dispensary in San Francisco's Mission District that was forced to close last month, has re-emerged as a delivery-only service, part of a growing trend in California's billion-dollar medical marijuana industry that's recently come under attack by federal authorities. Medithrive, a cannabis dispensary in San Francisco's Mission District that was forced to close last month, has re-emerged as a delivery-only service, part of a growing trend in California's billion-dollar medical marijuana industry that's recently come under attack by federal authorities.

Threats of property forfeiture, fines, lawsuits and raids this winter have made brick-and-mortar locations less enticing to pot entrepreneurs. Hundreds of storefronts have closed amid the new federal crackdown. Delivery services remain, offering a lower-profile, albeit more dangerous, alternative.