Not a message, but a date. There's this huge national exam called ENEM that is like SAT that every Brazilian in age to enter a college takes. Millions of students are taking it every year at the same date and time, as its result is what determines who enters in the best universities. Obviously, security against cheating is a huge concern and so everyone must have their phones turned off and sealed in a bag that stays in front of the class until they finish the exam. Now I can only imagine the chaos that would be if an alert was sent in that day.
Wouldn't. There isn't a single Brazilian who doesn't know Brazil's current world cup status. The entire country stops when there's a game. Nobody would fall for that.
"This is Army Commander Tomás Miguel Ribeiro Paiva. We have chosen to take command of the country to protect you against serious crimes against the people that we have become aware of. Remain calm and continue with your daily duties."
"Due to deteriorating economic conditions, we have decided to abolish currency altogether. The Real is now worth nothing. All trade will henceforth be performed exclusively in gold."
This is not a test. This is your emergency broadcast system announcing the commencement of the Annual Purge. Any and all crime, including murder, will be legal for 12 continuous hours.
mine would be something scifi, like "ALIENS HAVE LANDED" or "PLUTO DECLARES WAR"