You're right when it becomes to removal of children2

Children may not be removed from their home by police officers or social workers without notice and a hearing unless the officials have a reasonable belief that the children were in imminent danger. Ram v. Rubin, [9th Cir. 1997]

Absent extraordinary circumstances, a parent has a liberty interest in familial association and privacy that cannot be violated without adequate pre-deprivation procedures. An exparte hearing based on misrepresentation and omission does not constitute notice and an opportunity to be heard. Procurement of an order to seize a child through distortion, misrepresentation and/or omission is a violation of the Forth Amendment. Parents may assert their children’s Fourth Amendment claim on behalf of their children as well as asserting their own Fourteenth Amendment claim. Malik v.Arapahoe Cty. Dept. of Social Services, [10th Cir. 1999]

Plaintiff’s clearly established right to meaningful access to the courts would be violated by suppression of evidence and failure to report evidence. Chrissy v. Mississippi Dept. of Public Welfare, [5th Cir. 1991]

Mother had a clearly established right to an adequate, prompt post-deprivation hearing. A 17-day period prior to the hearing was not prompt hearing. Whisman V. Rinehart, [8th Cir. 1997