Actually 10% false positive rate is not that bad if the system really has a 90% chance of detecting child abuse. Keep in mind that it only raises a flag, it doesn't automatically results in a false conviction.
I don't have the numbers but I think that during an investigation, way more than 10% of suspects did nothing wrong. In fact, some people estimate that 10% of convictions are wrong (though I think that's an overestimate). A 90% effective system may actually end up preventing false arrests, search warrants, etc... a win for privacy!
The real concern is the potential for abuse, not that 90% bar that is, I think, completely reasonable.
Make sure you get the correct meaning of the 90%. This article isn't talking about a 10% false positive rate, which would mean that 10% of OK pictures are falsely flagged as bad. That would be awful. The article is actually talking about 90% precision, AKA 10% false discovery rate, which means that 10% of the pictures flagged as bad are actually OK. That's a fairly good precision - however it is only half the picture, as the false positive rate definitely needs to be specified (and be very low).
I don't have the numbers but I think that during an investigation, way more than 10% of suspects did nothing wrong. In fact, some people estimate that 10% of convictions are wrong (though I think that's an overestimate). A 90% effective system may actually end up preventing false arrests, search warrants, etc... a win for privacy!
The real concern is the potential for abuse, not that 90% bar that is, I think, completely reasonable.