Legal Question in Consumer Law in California

Yes they can. A debt "charge off " is nothing but an accounting entry that allows the original creditor to take a tax deduction for the money you owed and didn't repay. They can then still sell that debt, but now the payment for it is income. The buyer of the debt can then garnish wages or do any other legal thing to collect. If they get anything it is taxable income, less whatever they paid to buy the debt.