The national emergency alert system need password and username to log in. I don't think the government leave this system without any protection at all.
When you play CSGO on your laptop with headphones in school, and suddenly your headphones get disconnect then your laptop makes a huge ass sound " Bomb has been planted".
That person will get arrested. Government agencies don't have time to deal with Pewdiepie vs T-Series drama prank.
These fans are messing with the good people. Wait until these fans begin to messing with the bad guys on the deepweb that are making malware for money.