Unfortunately in this day and age, this could happen anywhere in the US, not just California
It is why you want to avoid ever getting the state involved if you can at all help it. Never let them in. Never answer their questions. Smiling. Always smiling.
I know this one involved the hospital so they were kind of stuck with what the hospital wanted to do.
But almost no one believes that.
Here's an experiment concept for all:
Spend about six weeks buying baby needs: diapers, formula, clothes, etc. (Put it all in the Good Will box when you're ready.) When it's good and cold outside, drop a dime on yourself. Call the CPS anonymously and say the perp (you) has no heat, has an infant, appears to be dealing drugs and/or prostitution, and the older kids are not in school.
See how long it takes to convince them to give back any kids you really have, or quit looking for the made-up one. See how long it takes them to access your bank records, credit records, purchasing history, medical history, gun ownership, contents of your medicine cabinet and fridge, internet activity, email...
Of course I don't really mean do this....false alarms are bad because the personnel could be diverted from a real emergency elsewhere. Just sayin.