California requires a separate unranked feed for every user under 16

An opt-out is a settings screen. One ranking service, a flag on the account, a chronological branch behind the flag. California's feed provisions prohibit serving minors content ranked on their own history and profile ^[2], so the under-16 account needs a ranking path it stays in, plus a routing decision made at signup by an age signal the platform trusts enough to act on. Australia is consulting on making platforms prompt users to switch ranking off ^[9].

The number product teams will reach for is Adam Mosseri's. He told an Australian briefing this week that engagement falls by half when users switch to a chronological feed ^[13]. TNW makes the right objection to using it here: the people who switch are self-selecting ^[20]. The figure describes users who went looking in settings and found the option. A 14-year-old routed to the unranked feed at signup only ever sees that one.

The accuracy of the whole thing is inherited. AB 1856 requires age verification signals in software applications ^[7], which pushes the check down into the operating system and the app store ^[8]. That is the layer Meta has spent two years arguing should carry a single age check ^[16]. TNW has also reported that Europe's child safety rules require collecting data its privacy laws forbid ^[22].

The chatbot half is where the lobbying shows. OpenAI publicly backed four of the bills ^[6], under a third of the 13 ^[3][14], and two days before signing it asked Congress for mandatory national AI safety rules, describing state legislation as a baseline Washington could later codify ^[15]. SB 1119 also carries independent child safety audits and annual risk assessments ^[5]. SB 867 regulates companion chatbots as toys, a product safety framing rather than a speech one ^[18]. "Innovation comes with responsibility, and protecting our children comes first," said Governor Gavin Newsom ^[12].

What you build depends on whether you can route on an age signal someone else generated, and on whether an unranked feed can fill a first session for an account with no history behind it. Both true, and the work is plumbing and a QA matrix. Signal good and feed empty, and the problem is cold start: regional popularity, follows, human curation. Feed good and signal weak, and you misroute in both directions, and the misroute that gets escalated is the 17-year-old dropped into the under-16 path. Neither true, and what ships is the toggle California removed ^[11].