“...claiming that an anonymous source called the state’s child abuse tipline and reported the family.”
So there is no grounds for reasonable suspicion or probable cause. Sue them for 4th amendment violations as well.
4th Amendment does not apply to CPS.
They can investigate you and take your children based on the word of people you will never be able to confront, question or have any chance to refute.
They can take your child and put them in a foster home with a pedophile and there is nothing you can do about it.
Welcome to INGSOC, better learn to love Big Brother.