Australia's world-first ban on social media for children under 16 has moved beyond domestic policy into a contest of sovereign authority, as Elon Musk's X formally challenges the country's proposed enforcement powers on grounds of international law. The dispute asks a question that no nation has yet answered cleanly: can a government meaningfully regulate platforms whose power, personnel, and legal allegiances lie beyond its borders? With a U.S. congressional committee already drawn into the fray and enforcement data showing the ban largely unenforced, what began as child protection legislatio