I have a tenant living in one of my rental properties in California and he has a cannabis card giving him permission to smoke Marijuana for a problem in his right arm and hand. While over at the property to do a repair I noticed that they are now growing plants in the garage. They have a little sophisticated growing setup in the garage but I don't know how many plants are inside. My question is how does this affect me as an owner and Landlord and what legal responsibilities do I have. Also what legal problems could be brought against me for knowing about it or allowing it? Can I make them get rid of the plants?