The nirvana fallacy and the case for friction in responding to online child sexual abuse

On 3 April 2026 the European Union’s temporary exception for voluntary detection of child sexual abuse material lapsed, and for three months the alternative that perfectionist arguments rarely state became policy: to do nothing. During the previous gap, in 2020–21, reports of abuse material from the EU fell by 58%. This article names the reasoning behind such outcomes as the nirvana fallacy, which Demsetz identified in 1969 as measuring the imperfect against an ideal instead of the real alternative. Four forms recur in the child-safety debate: circumvention, false positives, categorical impossibility and the slippery slope. Each states a real issue and leaves its comparator unstated. The article reframes the measures as friction, drawing on situational crime prevention, public health harm reduction and the economics of adversarial systems, then works along the offending pathway to set out what each friction layer achieves and what it cannot. Randomised trials and field deployments on Google Search, Pornhub and the Tor search engine Ahmia.fi show warnings reducing attempted access and increasing help-seeking, while hash matching, classifiers and age assurance carry known limits alongside measured effects. The article does not propose weakening encryption, and argues that most serious objections to other controls should be treated as design constraints rather than as refusals. A comparative test of four questions applies to objections and proposals alike, along with eight recommendations. Layered friction reduces measured offending-related behaviour at nearly every point it has been tested, and children are safer with it in the system than without it.