Former President Barack Obama signed a law in
2016 requiring FEMA to create a system that lets US presidents
send cellphone alerts regarding public safety issues like
natural disasters and terrorism.
US cellphone users will
not be able to opt out of the alert system. The test message on
Thursday, Oct 3, 2018 is scheduled for 2:18 p.m. EDT and will
read: "THIS IS A TEST of the National Wireless Emergency Alert
System. No action is needed."