If you own a U.S. mobile phone, you likely received a test alert in the new presidential alert warning system.  Why do I think nothing good can come of system by which Donald Trump could send out messages to 200 million phones at once?

FEMA controls the system, but the president can order alerts. Said BBC:


The trial is designed to check that a previously unused emergency communications system works properly.

Unlike other alerts – such as natural disaster warnings – there was no way to opt out, except switching a device off or blocking its cellular connection.