The news: Australia has enacted the world’s first nationwide prohibition on social media accounts for anyone under 16, targeting platforms including Instagram, Facebook, TikTok, YouTube, Snapchat, Reddit, and Twitch. The law requires companies to take “reasonable steps” to identify underage users and deactivate their accounts or face fines up to AUD 49.5 million (USD $32.65 million).

• Some teens are already shifting toward platforms not explicitly covered in the ban, like gaming platforms Roblox, Discord, and Steam, and Bytedance-owned Lemon8.
• Regulators note that evasion is expected and may push minors into less regulated digital spaces. The policy is designed as a live experiment: Officials, Stanford researchers, and an academic advisory group will study the effects on sleep, mental health, time offline, and migration to riskier environments, with findings to be made public.

How it works: Compliance plans differ by platform. TikTok will deactivate all under-16 accounts and hide prior posts; YouTube will sign out users until they turn 16; Snapchat will suspend accounts for three years or until eligibility; Meta has already removed underage accounts across its apps; and Twitch will block new accounts and shut down existing ones after a short delay. X continues to dispute the law and has not explained how it will comply.

Why it matters: The effects could extend well beyond Australia.

• In the US, likely presidential candidate Rahm Emanuel is calling for a similar under-16 ban framed as a matter of public health rather than free speech.
• According to recent polling, voters broadly support age restrictions, although younger adults are less convinced.
• Several US states have passed youth-safety laws—many tied up in litigation—and federal proposals range from banning under-13 use to curbing harmful features; Florida recently secured partial approval for its under-14 ban.

What it could mean US advertisers: Australia’s ban creates a real-time test of how age-gating at scale reshapes platform economics, youth discovery, and future advertising value. The US market should pay close attention.