You can think that, but it wasn't illegal. Everything was done within the law.
One shouldn't take away a single child, let alone a huge number of them, without probable case that the child is in danger. I don't think anyone alleges that any child under 13 is in danger - but why did they take all of them?
There was probable cause. That's why the judge approved the warrant. Furthermore, I believe there much of the evidence has not been leaked to the media. There are going to be multiple trials.
Moreover, you seem to have a cavalier attitude towards child abuse cases where the authorities act. I read more and more cases where nothing is done until the child is dead - and then everyone is asking "Where was everyone?"
Former FLDS members will be expert witnesses at the trials to events such as holding infants under water - "breaking babies" as Carolyn Jessop said on a recent television interview. Girls as young as 12 being added to the "Joy Book" putting them out there for "marriage" to the old men. Boys being abandoned once they reached puberty.
The state of Texas didn't create this mess. The FLDS did. You want the state to clean it up overnight?
This is what I have thought all along. I think there was more than a phone call that got them moving. Maybe there was to be a "weddng" that night or something?