[dragonwriter]

> The US has the amber alert protocol which also has a function for the president to dispatch any message (and can only be used by the president iirc), and that level of message can't be turned off via settings.

This is the Wireless Emergency Alert system, which carries Amber Alerts, Alerts about imminent threats to life/safety, and Presidential Alerts. The last (and only the last) can't be disabled in settings, because the legislation requiring support for the capacity required that Presidential alerts not be disabled. (The system is basically the mobile-device equivalent of the broadcast Emergency Alert System.)