Legal Question in Employment Law in California

If the employer compiled with a subpoena, and followed the rules regarding notice, there was no wrongdoing.

If instead privacy was violated and personal info disclosed, you might have a claim, but of what value?? The creditor has a right to collect his judgment, and could get all that info, and all your bank and asset and credit info by simply bringing a judgment Debtor Exam in court and the judge would force you to provide it all. The employer gave him nothing he wasn't entitled to, he just did it informally.