AUSTIN, Texas — Texas law provides for all children to be removed from a home if there's suspicion that one of them might have been abused, and that is what happened to the 437 children of Yearning for Zion ranch. But some experts worry that religious rights and family sanctity were trampled on the way out the door.

"I think it is an incredible and astounding exercise of police power," said civil rights attorney James Harrington.

The entire investigation was kicked off by what police now suspect was a hoax phone call, allegedly coming from within the Eldorado, Texas, polygamist compound by an abused 16-year-old. An extensive search warrant was issued, allowing police to rummage through every house in the large compound. In the end, hundreds of children were separated from their mothers.

Harrington said his immediate concern is for the children, who he suspects are traumatized and victimized.

"You can't take away a kid from their parents by saying, 'Hey, maybe later on there might be some abuse,"' he said. "It's a way of flipping the Constitution around so that they now have to prove they're innocent instead of the state having to prove they're guilty."

But this is civil law, and the fact is, the state law gives Child Protective Services a great deal of leeway, said Jack Sampson, a family law professor at the University of Texas law school.

The law sets a low threshold for removing a child from a potentially dangerous situation and urges judges to err on the side of caution.

"The department deemed the story told by the complainant to be a credible one and responded," Sampson said. "Whether it was a hoax or not from the victim is really irrelevant."

Once in the door, CPS conducted its own investigation, and presented evidence to state district Judge Barbara Walther that at least 20 women who lived in the compound were 16 or younger when they became pregnant.

"They responded and got all sorts of visible evidence as to what was going on in the compound," Sampson said. "You don't have to prove abuse at that first stage" where the state can win temporary custody of the children.

Kevin Dietz, a lawyer representing 45 mothers from the Fundamentalist LDS Church, said the state violated basic due process standards when it swept so many children from families without giving the parents an opportunity to respond.

Some of his clients received no notice from the court or CPS about the legal proceedings. "They had no meaningful way to participate and no evidence was presented against them," said Dietz, who works with Texas RioGrande Legal Aid.