http://www.dca.ca.gov/publications/landlordbook/sec-deposit.shtm

California law specifically allows the landlord to use a tenant's security deposit for four purposes:

• For unpaid rent;
• For cleaning the rental unit when the tenant moves out, but only to make the unit as clean as it was when the tenant first moved in;
• For repair of damages, other than normal wear and tear, caused by the tenant or the tenant's guests; and
• If the lease or rental agreement allows it, for the cost of restoring or replacing furniture, furnishings, or other items of personal property (including keys), other than because of normal wear and tear.