Auckland Council for Civil Liberties president Barry Wilson accused the minister of singling out people deemed to be undesirable and saying they should not have children, which is a technically accurate statement, but so carelessly loaded as to be a danger to traffic.
Former Green MP Sue Bradford discarded her customary good sense to invoke eugenics and speak of "state incursion into the reproductive lives of citizens".
Such extreme reactions are no more helpful than the language of talkback hosts who fulminate against "ferals" and use terms like "breeding" to speak of human reproduction. Bennett has welcomed public input and should be commended for doing so - not characterised as a would-be proponent of a latter-day master race.
All that said, the idea is wrong-headed, because it is impracticable and adds nothing of significance to the range of measures already available to people working in the social welfare and health systems.
The current regime requires Child, Youth and Family to obtain court orders for the custody of newborn babies - which the department did 148 times last year and 177 times in 2010 in respect of children in the first month of life.
The idea that such a dramatic step could be taken without first seeking a court's approval is deeply troubling and if the advocates of change say they need to streamline the process, they should improve their systems, not seek the removal of judicial oversight of such a draconian exercise of state power.
The idea of removing parents from children, rather than children from parents, is also logistically fraught. The vast majority of child abuse is perpetrated by men. Unlike the mothers, who are more likely to be linked to specific addresses and found with their children, "unfit" fathers are mobile and hard to track. Who would enforce any ban imposed on a man who may have children with multiple mothers and call multiple addresses home?
Good systems already exist to flag at-risk children. They can and should be improved, primarily by establishing more efficient information-sharing.
More important is the recognition of the social underprivilege that invariably accompanies extreme child abuse: domestic overcrowding, poverty, inter-generational unemployment.
As Auckland Hospital paediatrician Simon Rowley told Radio New Zealand National this week, "I don't think anyone sets out to abuse children and thinks 'I'm going to abuse this child but just in case they think I'm going to, I'll pretend that I'm not going to'."
Child abuse is fundamentally a societal not an individual failure. Protecting the kids must, of course, be the first priority.
Government shows it takes the issue seriously when it lets us inside its internal discussions. But this idea is too fraught to progress.