In practice, I imagine it would be in the minority of cases when law enforcement is given a report on someone including this detection "evidence," and for the d

In practice, I imagine it would be in the minority of cases when law enforcement is given a report on someone including this detection "evidence," and for the duration of the investigation the child is placed in protective custody. Not necessarily permanently, however the experience of family separation even for a few days can be traumatic. Criminal investigations can often take more than a few days of course. At the same time, there are unfortunately many counterexamples of abusive parents not being separated from their children via the same mechanisms. Sometimes this is from the abusers being "good criminals" and not getting caught; but sometimes it's from LEOs being bad LEOs and not doing the catching. My point was that in a system which surveils ~500M people, even an FP rate of ~0.01% is 50k people. Supposing the LEOs tasked with filtering this into credible (and triable) cases further manage to, through amazing police work, confirm the innocence of 99% of those false positives. That's still 500 falsely accused, but now confirmed suspicious, suspects.