A hoax 'alien invasion' alert in Brazil caused panic and amusement, revealing vulnerabilities in emergency systems. Authorities are investigating the breach.

Thousands of Brazilians received emergency alerts in the middle of the night warning of an "alien attack." Users received a flurry of push notifications mimicking government emergency alerts. It was ...

Add Yahoo as a preferred source to see more of our stories on Google. Imagine receiving an alert on your phone from a government agency at night, warning you about an alien attack, when you have ...