France has approved a ban on social media use by children under 15, the first blanket national prohibition in the European Union. Platforms would be blocked from opening new accounts for under-15s from 1 September and required to close existing ones within four months. The law is now before the Constitutional Council, referred by left-wing deputies, and does not take full effect until that review concludes.
The referral does not argue that minors are better off on these platforms. It argues that a blanket ban removes from every child under 15 a means of expression, information and participation in public life, and that a measure of that reach has to be proportionate to be constitutional. Opponents also raise a practical objection with a constitutional edge: verifying that a user is over 15 means verifying who everyone is, which ends anonymous use for adults as a side effect.
That side effect is the part worth watching, because it is the part that outlives the debate about children. Age assurance at this scale requires either document checks, a state identity layer, or inference from behaviour and biometrics. Each of those creates a record connecting a person to what they read and post, held by a platform or an intermediary, and once that infrastructure exists it does not stay limited to the purpose that justified it.
For platforms the compliance question is narrower and expensive. A French user base has to be age assured, existing accounts audited and closed, and the whole apparatus has to work well enough to satisfy a regulator without excluding adults who cannot or will not identify themselves.
France is deliberately ahead of Brussels here rather than waiting for a European instrument, which means the Constitutional Council's answer will be read across the union. A ruling that upholds the ban gives every other member state a template. One that strikes it down sets the boundary that any European version has to respect.